Exhibit 4.1

Execution Version

ION GEOPHYSICAL CORPORATION

AND EACH OF THE GUARANTORS PARTY HERETO

8.125% SENIOR SECURED SECOND PRIORITY NOTES DUE 2018

INDENTURE

Dated as of May 13, 2013

Wilmington Trust, National Association

as Trustee

U.S. Bank National Association

as Collateral Agent

N.A. means not applicable.

*  This Cross Reference Table is not part of the Indenture.

TABLE OF CONTENTS

EXHIBITS

INDENTURE dated as of May 13, 2013 is among ION Geophysical Corporation, a Delaware corporation, the Guarantors (as defined), Wilmington Trust, National Association, as trustee, and U.S. Bank National Association, as collateral agent.

The Company, the Guarantors, the Trustee and the Collateral Agent agree as follows for the benefit of each other and for the equal and ratable benefit of the Holders (as defined) of the 8.125% Senior Secured Second Priority Notes due 2018 (the “ Notes ”):

ARTICLE 1
DEFINITIONS AND INCORPORATION
BY REFERENCE

Section 1.01                              Definitions .

“144A Global Note” means a Global Note substantially in the form of Exhibit A hereto bearing the Global Note Legend and the Private Placement Legend and deposited with or on behalf of, and registered in the name of, the Depositary or its nominee that will be issued in a denomination equal to the outstanding principal amount of the Notes sold in reliance on Rule 144A.

“Acquired Debt” means, with respect to any specified Person:

(1)                                  Indebtedness of any other Person existing at the time such other Person is merged with or into or became a Subsidiary of such specified Person, whether or not such Indebtedness is incurred in connection with, or in contemplation of, such other Person merging with or into, or becoming a Restricted Subsidiary of, such specified Person; and

(2)                                  Indebtedness secured by a Lien encumbering any asset acquired by such specified Person.

“Act of Supermajority of Debtholders” means, as to any matter at any time:

(1)                                  prior to the Discharge of Priority Lien Obligations, a direction in writing delivered to the Priority Lien Collateral Agent by or with the written consent of the Holders of more than 66 2 / 3 % of the sum of: (a) the aggregate outstanding principal amount of Priority Lien Debt (including outstanding letters of credit whether or not then available or drawn); and (b) other than in connection with the exercise of remedies, the aggregate unfunded commitments to extend credit which, when funded, would constitute Priority Lien Debt; and

(2)                                  at any time after the Discharge of Priority Lien Obligations, a direction in writing delivered to the Collateral Agent by or with the written consent of the Holders of at least 66 2 / 3 % in aggregate principal amount of the Notes (including any Additional Notes) then outstanding.

“Additional Notes” means additional Notes (other than the Initial Notes) issued under this Indenture in accordance with Sections 2.02 and 4.09 hereof, as part of the same series as the Initial Notes.

“Affiliate” of any specified Person means any other Person directly or indirectly controlling or controlled by or under direct or indirect common control with such specified Person. For purposes of this definition, “control,” as used with respect to any Person, means the possession, directly or indirectly, of the power to direct or cause the direction of the management or policies of such Person, whether through the ownership of voting securities, by agreement or otherwise; provided that beneficial ownership of 10%

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or more of the Voting Stock of a Person shall be deemed to be control. For purposes of this definition, the terms “controlling,” “controlled by” and “under common control with” have correlative meanings.

“After-Acquired Property” means any and all assets or property acquired after the date of this Indenture, including any property or assets acquired by the Company or a Guarantor from another Guarantor, which in each case constitutes Collateral.

“Agent” means any Registrar, co-registrar, Paying Agent or additional paying agent.

“Applicable Premium” means, with respect to any Note on any redemption date, the greater of:

(1)                                  1.0% of the principal amount of the Note; or

(2)                                  the excess of:  (a) the present value at such redemption date of (i) the redemption price of the Note at May 15, 2015 (such redemption price being set forth in the table appearing in Section 3.07 hereof) plus (ii) all required interest payments due on the Note through May 15, 2015 (excluding accrued but unpaid interest to the redemption date), computed using a discount rate equal to the Treasury Rate as of such redemption date plus 50 basis points; over (b) the principal amount of the Note.

“Applicable Procedures” means, with respect to any transfer or exchange of or for beneficial interests in any Global Note, the rules and procedures of the Depositary, Euroclear and Clearstream that apply to such transfer or exchange.

“Asset Sale” means:

(1)                                  the sale, lease, conveyance or other disposition of any assets or rights by the Company or any of its Restricted Subsidiaries; provided that the sale, lease, conveyance or other disposition of all or substantially all of the assets of the Company and its Restricted Subsidiaries taken as a whole shall be governed by Sections 4.14 and/or 5.01 hereof; and

(2)                                  the issuance of Equity Interests by any of the Company’s Restricted Subsidiaries or the sale by the Company or any of its Restricted Subsidiaries of Equity Interests in any of the Company’s Subsidiaries (other than directors’ qualifying shares or shares required by applicable law to be held by a Person other than the Company or a Restricted Subsidiary).

Notwithstanding the preceding, none of the following items shall be deemed to be an Asset Sale:

(1)                                  any single transaction or series of related transactions that involves assets having a Fair Market Value of no more than $25.0 million since the date of this Indenture;

(2)                                  a transfer of assets between or among the Company and its Restricted Subsidiaries;

(3)                                  an issuance of Equity Interests by a Restricted Subsidiary of the Company to the Company or to a Restricted Subsidiary of the Company;

(4)                                  the sale, lease, license, sublicense or other transfer of assets, services or accounts receivable in the ordinary course of business and any sale or other disposition of damaged, worn-out or obsolete assets in the ordinary course of business (including the abandonment or other disposition of intellectual property that is, in the reasonable judgment of the Company, no longer

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economically practicable to maintain or useful in the conduct of the business of the Company and its Restricted Subsidiaries taken as whole);

(5)                                  licenses and sublicenses by the Company or any of its Restricted Subsidiaries of software or intellectual property in the ordinary course of business;

(6)                                  any surrender or waiver of contract rights or settlement, release, recovery on or surrender of contract, tort or other claims in the ordinary course of business;

(7)                                  the granting of Liens not prohibited by Section 4.12 hereof and the sale or other disposition pursuant to foreclosure of the assets subject to such Lien;

(8)                                  the sale or other disposition of cash, Cash Equivalents, Hedging Obligations or other financial instruments;

(9)                                  any sale of Capital Stock, Indebtedness or other securities of an Unrestricted Subsidiary; and

(10)                           a Restricted Payment that does not violate Section 4.07 hereof or a Permitted Investment (or a disposition that would constitute a Restricted Payment but for the exclusion from the definition thereof).

“Attributable Debt” in respect of a sale and leaseback transaction means, at the time of determination, the present value of the obligation of the lessee for net rental payments during the remaining term of the lease included in such sale and leaseback transaction including any period for which such lease has been extended or may, at the option of the lessor, be extended. Such present value shall be calculated using a discount rate equal to the rate of interest implicit in such transaction, determined in accordance with GAAP; provided, however , that if such sale and leaseback transaction results in a Capital Lease Obligation, the amount of Indebtedness represented thereby shall be determined in accordance with the definition of “Capital Lease Obligation.”

“Bankruptcy Law” means Title 11, U.S. Code or any similar federal or state law for the relief of debtors.

“Beneficial Owner” has the meaning assigned to such term in Rule 13d-3 and Rule 13d-5 under the Exchange Act, except that in calculating the beneficial ownership of any particular “person” (as that term is used in Section 13(d)(3) of the Exchange Act), such “person” shall be deemed to have beneficial ownership of all securities that such “person” has the right to acquire by conversion or exercise of other securities, whether such right is currently exercisable or is exercisable only after the passage of time. The terms “Beneficially Owns” and “Beneficially Owned” have a corresponding meaning.

“Board of Directors” means:

(1)                                  with respect to a corporation, the board of directors of the corporation or any committee thereof duly authorized to act on behalf of such board;

(2)                                  with respect to a partnership, the Board of Directors of the general partner of the partnership;

(3)                                  with respect to a limited liability company, the managing member or members or any controlling committee of managing members thereof; and

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(4)                                  with respect to any other Person, the board or committee of such Person serving a similar function.

“Broker-Dealer” means any broker or dealer, in either case, that is registered under the Exchange Act.

“Business Day” means any day other than a Legal Holiday.

“Capital Lease Obligation” means, at the time any determination is to be made, the amount of the liability in respect of a capital lease that would at that time be required to be capitalized on a balance sheet prepared in accordance with GAAP, and the Stated Maturity thereof shall be the date of the last payment of rent or any other amount due under such lease prior to the first date upon which such lease may be prepaid by the lessee without payment of a penalty. Notwithstanding the foregoing, any lease (whether entered into before or after the date of this Indenture) that would have been classified as an operating lease pursuant to GAAP as in effect on the date of this Indenture shall be deemed not to represent a Capital Lease Obligation.

“Capital Stock” means:

(1)                                  in the case of a corporation, corporate stock;

(2)                                  in the case of an association or business entity, any and all shares, interests, participations, rights or other equivalents (however designated) of corporate stock;

(3)                                  in the case of a partnership or limited liability company, partnership interests (whether general or limited) or membership interests; and

(4)                                  any other interest or participation that confers on a Person the right to receive a share of the profits and losses of, or distributions of assets of, the issuing Person, but excluding from all of the foregoing any debt securities convertible into Capital Stock, whether or not such debt securities include any right of participation with Capital Stock.

“Cash Equivalents” means:

(1)                                  United States dollars;

(2)                                  securities issued or directly and fully guaranteed or insured by the United States government or any agency or instrumentality of the United States government ( provided that the full faith and credit of the United States is pledged in support of those securities) having maturities of not more than six months from the date of acquisition;

(3)                                  certificates of deposit and eurodollar time deposits with maturities of six months or less from the date of acquisition, bankers’ acceptances with maturities not exceeding six months and overnight bank deposits, in each case, with any lender party to the Credit Agreement or with any domestic commercial bank having capital and surplus in excess of $500.0 million and a Thomson Bank Watch Rating of “B” or better;

(4)                                  repurchase obligations with a term of not more than thirty days for underlying securities of the types described in clauses (2) and (3) above entered into with any financial institution meeting the qualifications specified in clause (3) above;

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(5)                                  commercial paper having one of the two highest ratings obtainable from Moody’s or S&P and, in each case, maturing within one year after the date of acquisition;

(6)                                  money market funds at least 95% of the assets of which constitute Cash Equivalents of the kinds described in clauses (1) through (5) of this definition;

(7)                                  money market funds that (i) comply with the criteria set forth in Securities and Exchange Commission Rule 2a-7 under the Investment Company Act of 1940, (ii) are rated or invest solely in the assets described in clauses (1) through (6) above and (iii) have portfolio assets of at least $500.0 million;

(8)                                  marketable direct obligations issued by any state of the United States of America or any political subdivision of any such state or any public instrumentality thereof, in each case maturing within one year after the date of acquisition and having, at such date, the highest rating obtainable from either S&P or Moody’s;

(9)                                  any interest bearing account at, or certificate of deposit maturing not more than one year after such time issued by, a U.S. savings and loan association which has a rating of “A-” or better from S&P or a rating of “A3” or better from Moody’s on its long term unsecured debt and which has combined capital and surplus and undivided profits of not less than $500.0 million;

(10)                           any interest bearing account at, or certificate of deposit maturing not more than one year after such time, payable in United Stated dollars and issued by, (i) a foreign banking institution or foreign branch of a U.S. banking institution, which banking institution has a rating of “A-” or better from S&P or a rating of “A3” or better from Moody’s on its long-term unsecured debt and combined capital and surplus and undivided profits of not less than $500.0 million, or (ii) any foreign subsidiary of a U.S. banking institution, which U.S. banking institution has a rating of “A-” or better from S&P or a rating of “A3” or better from Moody’s and which subsidiary has combined capital and surplus and undivided profits of not less than $500.0 million;

(11)                           any evidence of Indebtedness (including variable rate demand notes), maturing not more than one year after such time, issued by any State of the United States, by any county or municipality organized or incorporated under the laws of any State of the United States or by any agency or subdivision of any of the foregoing, in each case rated “A-” or better by S&P or rated “A3” or better by Moody’s;

(12)                           any preferred securities issued by domestic or foreign corporations, municipalities, or closed-end management investment companies and are designed as short term money market instruments rated “A-” or better by S&P or rated “A3” or better by Moody’s, provided that such Investment will not result in any violation of F.R.S. Board Regulation U and further provided that the Company’s aggregate ownership interest of all of the Guarantors does not exceed (and is not convertible into shares which exceed 5% of the issuer’s outstanding shares entitled to vote unless such ownership interest is acquired pursuant to a merger agreement between or among the Company and/or one or more Guarantors and such issuer);

(13)                           any mutual funds or similar investment vehicles investing primarily in Investments of the types set forth in the foregoing clauses (1) through (12), provided that ratings requirements shall be applicable to the mutual fund rather than the underlying Investments, as follows: such mutual funds shall, in each case, have a rating of “A-” or better from S&P or a rating of “A3” from Moody’s, provided , however , that it is agreed that (i) any Investment which

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when made complies with the requirements of any of the foregoing clauses (7), (8), (9), (10), (11) or (12) may continue to be held notwithstanding that such Investment if made thereafter would not comply with such requirements; and (ii) no Investment otherwise permitted by clauses (12) or (13) shall be permitted to be made directly or indirectly through a mutual fund if, immediately before or after giving effect thereto, any Default shall have occurred and be continuing; and

(14)                           with respect to the Subsidiaries that are not Domestic Subsidiaries only, any Investments outside of the United States that are the functional foreign equivalents in all material respects to the investments described in the foregoing clauses (1) through (13) of this definition.

“Change of Control” means the occurrence of any of the following:

(1)                                  the direct or indirect sale, lease, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or a series of related transactions, of all or substantially all of the properties or assets of the Company and its Subsidiaries taken as a whole to any Person (including any “person” (as that term is used in Section 13(d)(3) of the Exchange Act));

(2)                                  the adoption of a plan relating to the liquidation or dissolution of the Company;

(3)                                  the consummation of any transaction (including, without limitation, any merger or consolidation), the result of which is that any Person (including any “person” (as defined above) becomes the Beneficial Owner, directly or indirectly, of more than 50% of the Voting Stock of the Company, measured by voting power rather than number of shares; or

(4)                                  the first day on which a majority of the members of the Board of Directors of the Company are not Continuing Directors.

Notwithstanding the preceding, the conversion of the Company from a corporation to a limited liability company, limited partnership or other form of entity or an exchange of all of the outstanding Equity Interests in one form of entity for Equity Interests in another form of entity shall not constitute a Change of Control, so long as such transaction otherwise complies with the terms of this Indenture and following such conversion or exchange the “persons” (as that term is used in Section 13(d)(3) of the Exchange Act) who Beneficially Owned the Capital Stock of the Company immediately prior to such transactions continue to Beneficially Own in the aggregate more than 50% of the Voting Stock of the Company, or continue to Beneficially Own sufficient Equity Interests in such entity to elect a majority of its directors, managers, trustees or other persons serving in a similar capacity for such entity or its general partner, as applicable, and, in either case no “person” Beneficially Owns more than 50% of the Voting Stock of such entity or its general partner, as applicable.

“Clearstream” means Clearstream Banking, S.A.

“Class” means (1) in the case of Parity Lien Debt, all Parity Lien Debt, taken together, and (2) in the case of Priority Lien Debt, every Series of Priority Lien Debt, taken together.

“Collateral” means all properties and assets at any time owned or acquired by the Company or any of the other Guarantors, except:

(1)                                  Excluded Assets;

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(2)                                  any properties and assets in which the Collateral Agent is required to release its Liens pursuant to the provisions described in Section 5.1 of the Intercreditor Agreement; and

(3)                                  any properties and assets that no longer secure the Notes or any Obligations in respect thereof pursuant to the provisions described in Section 10.04 hereof;

provided that in the case of clauses (2) and (3), if such Liens are required to be released as a result of the sale, transfer or other disposition of any properties or assets of the Company or any other Guarantor, such assets or properties shall cease to be excluded from the Collateral if the Company or any other Guarantor thereafter acquires or reacquires such assets or properties.

“Collateral Agent” means U.S. Bank National Association, in its capacity as collateral agent, until a successor replaces it in accordance with the applicable provisions of this Indenture and thereafter means the successor serving hereunder.

“Company” means ION Geophysical Corporation, and any and all successors thereto.

“Consolidated EBITDA” means, with respect to any specified Person for any period, the Consolidated Net Income of such Person for such period plus , without duplication:

(1)                                  an amount equal to any extraordinary loss plus any net loss realized by such Person or any of its Restricted Subsidiaries in connection with an Asset Sale, to the extent such losses were deducted in computing such Consolidated Net Income; plus

(2)                                  provision for taxes based on income or profits of such Person and its Restricted Subsidiaries for such period, to the extent that such provision for taxes was deducted in computing such Consolidated Net Income; plus

(3)                                  the Fixed Charges of such Person and its Restricted Subsidiaries for such period, to the extent that such Fixed Charges were deducted in computing such Consolidated Net Income; plus

(4)                                  any foreign currency translation losses (including losses related to currency remeasurements of Indebtedness) of such Person and its Restricted Subsidiaries for such period, to the extent that such losses were taken into account in computing such Consolidated Net Income; plus

(5)                                  the aggregate reserves established by the Company with respect to the WesternGeco L.L.C. v. ION Geophysical Corporation litigation, plus

(6)                                  depreciation, amortization (including amortization of intangibles but excluding amortization of prepaid cash expenses that were paid in a prior period) and other non-cash charges and expenses (excluding any such non-cash charge or expense to the extent that it represents an accrual of or reserve for cash charges or expenses in any future period or amortization of a prepaid cash charge or expense that was paid in a prior period) of such Person and its Restricted Subsidiaries for such period to the extent that such depreciation, amortization and other non-cash charges or expenses were deducted in computing such Consolidated Net Income; minus

(7)                                  any foreign currency translation gains (including gains related to currency remeasurements of Indebtedness) of such Person and its Restricted Subsidiaries for such period,

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to the extent that such gains were taken into account in computing such Consolidated Net Income; minus

(8)                                  non-cash items increasing such Consolidated Net Income for such period, other than the accrual of revenue in the ordinary course of business;

in each case, on a consolidated basis and determined in accordance with GAAP.

Notwithstanding the preceding, the provision for taxes based on the income or profits of, and the depreciation and amortization and other non-cash expenses of, a Restricted Subsidiary of the Company shall be added to Consolidated Net Income to compute Consolidated EBITDA of the Company only to the extent that a corresponding amount would be permitted at the date of determination to be dividended to the Company by such Restricted Subsidiary without prior governmental approval (that has not been obtained), and without direct or indirect restriction pursuant to the terms of its charter and all agreements, instruments, judgments, decrees, orders, statutes, rules and governmental regulations applicable to that Restricted Subsidiary or its stockholders.

“Consolidated Indebtedness” means, as of any date of determination, an amount equal to the aggregate principal amount of Indebtedness of the Company and its Restricted Subsidiaries outstanding on such date, determined on a consolidated basis in accordance with GAAP.

“Consolidated Net Income” means, with respect to any specified Person for any period, the aggregate net income (loss) of such Person and its Restricted Subsidiaries for such period, on a consolidated basis, determined in accordance with GAAP and without any reduction in respect of preferred stock dividends; provided that:

(1)                                  all extraordinary gains and losses and all gains and losses realized in connection with any Asset Sale or the disposition of securities or the early extinguishment of Indebtedness, together with any related provision for taxes on any such gain, shall be excluded;

(2)                                  the net income of any Person that is not a Restricted Subsidiary or that is accounted for by the equity method of accounting shall be included only to the extent of the amount of dividends or similar distributions paid in cash to the specified Person or a Restricted Subsidiary of the Person;

(3)                                  the net income (but not loss) of any Restricted Subsidiary other than a Guarantor shall be excluded to the extent that the declaration or payment of dividends or similar distributions by that Restricted Subsidiary of that net income is not at the date of determination permitted without any prior governmental approval (that has not been obtained) or, directly or indirectly, by operation of the terms of its charter or any agreement, instrument, judgment, decree, order, statute, rule or governmental regulation applicable to that Restricted Subsidiary or its stockholders;

(4)                                  the cumulative effect of a change in accounting principles shall be excluded; and

(5)                                  non-cash gains and losses attributable to movement in the mark-to-market valuation of Hedging Obligations pursuant to Financial Accounting Standards Board Accounting Standards Codification 815 (“ ASC 815 ”) shall be excluded.

“Consolidated Net Tangible Assets” means, with respect to any specified Person as of any date of determination, the consolidated total assets of such Person and its Restricted Subsidiaries determined in

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accordance with GAAP as of the end of the Person’s most recent fiscal quarter for which internal financial statements are available, less the sum of (1) all current liabilities and current liability items, and (2) all goodwill, trade names, trademarks, patents, organization expense, unamortized debt discount and expense and other similar intangibles properly classified as intangibles in accordance with GAAP.

“continuing” means, with respect to any Default or Event of Default, that such Default or Event of Default has not been cured or waived.

“Continuing Directors ” means, as of any date of determination, any member of the Board of Directors of the Company who:

(1)                                  was a member of such Board of Directors on the date of this Indenture; or

(2)                                  was nominated for election or elected to such Board of Directors with the approval of a majority of the Continuing Directors who were members of such Board of Directors at the time of such nomination or election.

“Corporate Trust Office of the Trustee” means the address of the Trustee specified in Section 13.02 hereof or such other address as to which the Trustee may give notice to the Company.

“Credit Agreement” means that certain Credit Agreement, dated as of March 25, 2010, by and among the Company and China Merchants Bank Co., Ltd., New York Branch, as administrative agent and lender, as amended, including any related notes, Guarantees, collateral documents, instruments and agreements executed in connection therewith, and, in each case, as further amended, restated, modified, renewed, refunded, replaced in any manner (whether upon or after termination or otherwise) or refinanced (including by means of sales of debt securities to institutional investors) in whole or in part from time to time.

“Credit Agreement Agent” means, at any time, the Person serving at such time as the “Agent” or “Administrative Agent” under the Credit Agreement or any other representative then most recently designated in accordance with the applicable provisions of the Credit Agreement, together with its successors in such capacity.

“Credit Facilities” means, one or more debt facilities (including, without limitation, any Credit Agreement), indentures, commercial paper facilities or secured or unsecured capital market financing, in each case, with banks or other institutional lenders or institutional investors providing for revolving credit loans, term loans, term debt, debt securities, receivables financing (including through the sale of receivables to such lenders or to special purpose entities formed to borrow from such lenders against such receivables) or letters of credit, in each case, as amended, restated, modified, renewed, extended, increased, refunded, replaced in any manner (whether upon or after termination or otherwise) or refinanced (including by means of sales of debt securities to institutional investors) in whole or in part from time to time.

“Customary Recourse Exceptions” means, with respect to any Non-Recourse Debt of an Unrestricted Subsidiary, exclusions from the exculpation provisions with respect to such Non-Recourse Debt for the voluntary bankruptcy of such Unrestricted Subsidiary, fraud, misapplication of cash, environmental claims, waste, willful destruction and other circumstances customarily excluded by lenders from exculpation provisions or included in separate indemnification agreements in non-recourse financings.

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“Custodian” means the Trustee, as custodian with respect to the Notes in global form, or any successor entity thereto.

“Deemed Capitalized Leases” means obligations of the Company or any Restricted Subsidiary of the Company that are classified as “capital lease obligations” under GAAP due to the application of ASC Topic 840 or any subsequent pronouncement having similar effect and, except for such regulation or pronouncement, such obligation would not constitute a Capital Lease Obligation.

“Default” means any event that is, or with the passage of time or the giving of notice or both would be, an Event of Default.

“Definitive Note” means a certificated Note registered in the name of the Holder thereof and issued in accordance with Section 2.06 hereof, substantially in the form of Exhibit A hereto except that such Note shall not bear the Global Note Legend and shall not have the “Schedule of Exchanges of Interests in the Global Note” attached thereto.

“Depositary” means, with respect to the Notes issuable or issued in whole or in part in global form, the Person specified in Section 2.03 hereof as the Depositary with respect to the Notes, and any and all successors thereto appointed as depositary hereunder and having become such pursuant to the applicable provision of this Indenture.

“De Minimis Guaranteed Amount” means a principal amount of Indebtedness that does not exceed $5.0 million.

“Discharge of Parity Lien Obligations” has the meaning given to the term “Discharge of Second Lien Obligations” in the Intercreditor Agreement.

“Discharge of Priority Lien Obligations” has the meaning given to the term “Discharge of First Lien Obligations” in the Intercreditor Agreement.

“Disqualified Stock” means any Capital Stock that, by its terms (or by the terms of any security into which it is convertible, or for which it is exchangeable, in each case, at the option of the holder of the Capital Stock), or upon the happening of any event, matures or is mandatorily redeemable, pursuant to a sinking fund obligation or otherwise, or redeemable at the option of the holder of the Capital Stock, in whole or in part, on or prior to the date that is 91 days after the date on which the Notes mature; provided , however , that any class of Capital Stock of such Person that by its terms authorizes such Person to satisfy in full its obligations with respect to the payment of dividends or upon maturity, redemption (pursuant to a sinking fund or otherwise) or repurchase thereof or otherwise by the delivery of Capital Stock that is not Disqualified Stock, and that is not convertible, puttable or exchangeable for Disqualified Stock so long as such Person satisfies its obligations with respect thereto solely by the delivery of Capital Stock that is not Disqualified Stock. Notwithstanding the preceding sentence, any Capital Stock that would constitute Disqualified Stock solely because the holders of the Capital Stock have the right to require the Company to repurchase such Capital Stock upon the occurrence of a change of control or an asset sale shall not constitute Disqualified Stock if the terms of such Capital Stock provide that the Company may not repurchase or redeem any such Capital Stock pursuant to such provisions unless such repurchase or redemption complies with Section 4.07 hereof. The amount of Disqualified Stock deemed to be outstanding at any time for purposes of this Indenture shall be the maximum amount that the Company and its Restricted Subsidiaries may become obligated to pay upon the maturity of, or pursuant to any mandatory redemption provisions of, such Disqualified Stock, exclusive of accrued dividends.

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“Domestic Subsidiary” means any Restricted Subsidiary of the Company that was formed under the laws of the United States or any state of the United States or the District of Columbia or that guarantees or otherwise provides direct credit support for any Indebtedness of the Company.

“Enforcement Action” shall have the meaning set forth in the Intercreditor Agreement.

“equally and ratably” means, in reference to sharing of Liens or proceeds thereof as between holders of Secured Obligations within the same Class, that such Liens or proceeds:

(1)                                  shall be allocated and distributed first to the Secured Debt Representative for each outstanding Series of Secured Debt within that Class, for the account of the holders of such Series of Secured Debt, ratably in proportion to the principal of, and interest and premium (if any) and reimbursement obligations (contingent or otherwise) with respect to letters of credit, if any, outstanding (whether or not drawings have been made under such letters of credit) on each outstanding Series of Secured Debt within that Class when the allocation or distribution is made, and thereafter

(2)                                  shall be allocated and distributed (if any remain after payment in full of all of the principal of, and interest and premium (if any) and reimbursement obligations (contingent or otherwise) with respect to letters of credit, if any, outstanding (whether or not drawings have been made on such letters of credit) on all outstanding Secured Obligations within that Class) to the Secured Debt Representative for each outstanding Series of Secured Obligations within that Class, for the account of the holders of any remaining Secured Obligations within that Class, ratably in proportion to the aggregate unpaid amount of such remaining Secured Obligations within that Class due and demanded (with written notice to the applicable Secured Debt Representative, the Priority Lien Collateral Agent and the Collateral Agent) prior to the date such distribution is made.

“Equity Interests” means Capital Stock and all warrants, options or other rights to acquire Capital Stock (but excluding any debt security that is convertible into, or exchangeable for, Capital Stock).

“Equity Offering” means a public or private sale of Equity Interests of the Company by the Company (other than Disqualified Stock and other than to a Subsidiary of the Company) made on a primary basis by the Company after the date of this Indenture.

“Euroclear” means Euroclear Bank, S.A./N.V., as operator of the Euroclear system.

“Exchange Act” means the Securities Exchange Act of 1934, as amended.

“Exchange Notes” means the Notes issued in an Exchange Offer pursuant to Section 2.06(f) hereof.

“Exchange Offer” has the meaning set forth in the applicable Registration Rights Agreement.

“Exchange Offer Registration Statement” has the meaning set forth in the applicable Registration Rights Agreement.

“Excluded Assets” means each of the following:

(1)                                  any asset or property right of the Company or any Guarantor of any nature:

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(a)                                  if the grant of a security interest shall constitute or result in (i) the abandonment, invalidation or unenforceability of such asset or property right or the Company’s or any Guarantor’s loss of use of such asset or property right or (ii) a breach, termination or default under any lease, license, contract or agreement (other than to the extent that any such term would be rendered ineffective pursuant to Sections 9-406, 9-407, 9-408 or 9-409 of the UCC (or any successor provision or provisions) of any relevant jurisdiction or any other applicable law (including the United States Bankruptcy Code) or principles of equity) to which the Company or such Guarantor is party; and

(b)                                  to the extent that any applicable law or regulation prohibits the creation of a security interest thereon (other than to the extent that any such term would be rendered ineffective pursuant to any applicable law or principles of equity);

(2)                                  Capital Stock of any Foreign Subsidiary that is directly owned by the Company or any Guarantor, and any disregarded entity owner (direct or indirect through one or more other disregarded entities) of such Foreign Subsidiary, other than Voting Stock in ION International Holdings L.P. solely to the extent representing in excess of 65% of the total voting power of all outstanding Voting Stock of such Foreign Subsidiary or such disregarded entity owner and all Capital Stock of Foreign Subsidiaries not directly owned by any Person that is the Company or a Guarantor;

(3)                                  any applications for trademarks or service marks filed in the United States Patent and Trademark Office (the “ PTO ”) pursuant to 15 U.S.C. § 1051 Section 1(b) unless and until evidence of use of the mark in interstate commerce is submitted to the PTO pursuant to 15 U.S.C. § 1051 Section 1(c) or Section 1(d);

(4)                                  fixed or capital assets owned by the Company or any Guarantor that is subject to a capital lease or purchase money obligations, in each case permitted to be incurred pursuant to Sections 4.09 and 4.12 hereof if the contract or other agreement in which such Lien is granted prohibits the creation of any other Lien on such fixed or capital assets, but only for so long as such prohibition is in effect and only with respect to the portion of such fixed or capital assets as to which such other Lien attaches and such prohibition applies;

(5)                                  motor vehicles;

(6)                                  any Capital Stock of any Subsidiary to the extent (and only to the extent) that in the reasonable judgment of the Company, if such Capital Stock were not excluded from the Collateral then Rule 3-16 or Rule 3-10 of Regulation S-X under the Securities Act would require the filing of separate financial statements of such Subsidiary with the SEC (or any other governmental agency) in connection with a registration of the Notes under the Securities Act;

(7)                                  de minimis or immaterial assets for which perfection of the security could not be obtained without unreasonable cost and expense or under applicable law;

(8)                                  unless such real property and fixtures (a) secure the Credit Agreement and (b) have a fair market value in excess of $10.0 million, real property and any fixtures owned or leased by the Company or any other Guarantor;

(9)                                  the INOVA Letter of Credit;

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(10)                           unless such Equity Interests secure the Credit Agreement, Equity Interests in any Person other than (a) a Guarantor, to the extent such Person is at such time a Guarantor, and (b) as provided in clause (2) of this definition;

(11)                           any account (and any cash, Cash Equivalents or other investments deposited therein) securing Indebtedness described in Section 4.09(b)(xx) hereof; and

(12)                           prior to the Discharge of Priority Lien Obligations, any property not subject to a Lien securing the Credit Agreement.

“Existing Indebtedness” means all Indebtedness of the Company and its Subsidiaries (other than Indebtedness under the Credit Agreement) in existence on the date of this Indenture, until such amounts are repaid.

“Existing Priority Lien Security Agreement” means that certain Security and Pledge Agreement (Domestic Indebtedness) dated as of March 25, 2010, among the Company, the Guarantors and China Merchants Bank Co., Ltd., New York Branch.

“Fair Market Value” means the value that would be paid by a willing buyer to an unaffiliated willing seller in a transaction not involving distress or necessity of either party, determined in good faith by the Board of Directors of the Company in the case of amounts of $40 million or more and otherwise by an Officer of the Company (unless otherwise provided in this Indenture).

“Fixed Charge Coverage Ratio” means with respect to any specified Person for any period, the ratio of the Consolidated EBITDA of such Person for such period to the Fixed Charges of such Person for such period. In the event that the specified Person or any of its Restricted Subsidiaries incurs, assumes, guarantees, repays, repurchases, redeems, defeases or otherwise discharges any Indebtedness (other than ordinary working capital borrowings) or issues, repurchases or redeems preferred stock subsequent to the commencement of the period for which the Fixed Charge Coverage Ratio is being calculated and on or prior to the date on which the event for which the calculation of the Fixed Charge Coverage Ratio is made (the “ Calculation Date ”), then the Fixed Charge Coverage Ratio shall be calculated giving pro forma effect to such incurrence, assumption, Guarantee, repayment, repurchase, redemption, defeasance or other discharge of Indebtedness, or such issuance, repurchase or redemption of preferred stock, and the use of the proceeds therefrom, as if the same had occurred at the beginning of the applicable four-quarter reference period.

In addition, for purposes of calculating the Fixed Charge Coverage Ratio:

(1)                                  acquisitions that have been made by the specified Person or any of its Restricted Subsidiaries, including through mergers or consolidations, or any Person or any of its Restricted Subsidiaries acquired by the specified Person or any of its Restricted Subsidiaries, and including all related financing transactions and including increases in ownership of Restricted Subsidiaries, during the four-quarter reference period or subsequent to such reference period and on or prior to the Calculation Date, or that are to be made on the Calculation Date, shall be given pro forma effect as if they had occurred on the first day of the four-quarter reference period;

(2)                                  the Consolidated EBITDA attributable to discontinued operations, as determined in accordance with GAAP, and operations or businesses (and ownership interests therein) disposed of prior to the Calculation Date, shall be excluded;

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(3)                                  the Fixed Charges attributable to discontinued operations, as determined in accordance with GAAP, and operations or businesses (and ownership interests therein) disposed of prior to the Calculation Date, shall be excluded, but only to the extent that the obligations giving rise to such Fixed Charges will not be obligations of the specified Person or any of its Restricted Subsidiaries following the Calculation Date;

(4)                                  any Person that is a Restricted Subsidiary on the Calculation Date shall be deemed to have been a Restricted Subsidiary at all times during such four-quarter period;

(5)                                  any Person that is not a Restricted Subsidiary on the Calculation Date shall be deemed not to have been a Restricted Subsidiary at any time during such four-quarter period; and

(6)                                  if any Indebtedness bears a floating rate of interest, the interest expense on such Indebtedness shall be calculated as if the rate in effect on the Calculation Date had been the applicable rate for the entire period (taking into account any Hedging Obligation applicable to such Indebtedness if such Hedging Obligation has a remaining term as at the Calculation Date in excess of 12 months).

For purposes of this definition, whenever pro forma effect is to be given to any calculation under this definition, the pro forma calculations shall be determined in good faith by a responsible financial or accounting Officer of the Company, which determination shall be conclusive for all purposes under this Indenture; provided that such Officer may in such Officer’s discretion include any reasonably identifiable and factually supportable pro forma changes to Consolidated Cash Flow or Fixed Charges, including any pro forma expense and cost reductions or synergies that have occurred or are reasonably expected to occur within the 12 months immediately following the Calculation Date and are either (i) prepared and calculated in accordance with Regulation S-X under the Securities Act or (ii) set forth in an Officers’ Certificate signed by the chief financial or accounting officer that states (a) the amount of each such adjustment and (b) that such adjustments are based on the reasonable good faith belief of the Officers executing such Officers’ Certificate at the time of such execution and the factual basis on which such good faith belief is based.

“Fixed Charges” means, with respect to any specified Person for any period, the sum, without duplication, of:

(1)                                  the consolidated interest expense of such Person and its Restricted Subsidiaries for such period, whether paid or accrued, including, without limitation, amortization of debt issuance costs and original issue discount, non-cash interest payments, the interest component of any deferred payment obligations, the interest component of all payments associated with Capital Lease Obligations (but excluding any interest expense attributable to Deemed Capitalized Leases), imputed interest with respect to Attributable Debt, commissions, discounts and other fees and charges incurred in respect of letter of credit or bankers’ acceptance financings, and net of the effect of all payments made or received pursuant to Hedging Obligations in respect of interest rates; plus

(2)                                  the consolidated interest expense of such Person and its Restricted Subsidiaries that was capitalized during such period; plus

(3)                                  any interest on Indebtedness of another Person that is guaranteed by such Person or one of its Restricted Subsidiaries or secured by a Lien on assets of such Person or one of its Restricted Subsidiaries, to the extent such Guarantee or Lien is called upon (other than a Lien of the type described in clause (9) of the definition of Permitted Liens); plus

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(4)                                  all dividends, whether paid or accrued and whether or not in cash, on any series of preferred stock of such Person or any of its Restricted Subsidiaries, other than dividends on Equity Interests payable solely in Equity Interests of the Company (other than Disqualified Stock) or to the Company or a Restricted Subsidiary of the Company.

“Foreign Subsidiary” means any Restricted Subsidiary of the Company that is not a Domestic Subsidiary.

“GAAP” means generally accepted accounting principles set forth in the opinions and pronouncements of the Accounting Principles Board of the American Institute of Certified Public Accountants and statements and pronouncements of the Financial Accounting Standards Board or in such other statements by such other entity as have been approved by a significant segment of the accounting profession, which are in effect on the date of this Indenture.

“Global Note Legend” means the legend set forth in Section 2.06(g)(ii) hereof, which is required to be placed on all Global Notes issued under this Indenture.

“Global Notes” means, individually and collectively, each of the Restricted Global Notes and the Unrestricted Global Notes deposited with or on behalf of and registered in the name of the Depository or its nominee, substantially in the form of Exhibit A hereto and that bears the Global Note Legend and that has the “Schedule of Exchanges of Interests in the Global Note” attached thereto, issued in accordance with Section 2.01, 2.06(b)(iii), 2.06(b)(iv), 2.06(d)(ii) or 2.06(f) hereof.

“Government Securities” means direct obligations of, or obligations guaranteed by, the United States of America, and the payment for which the United States pledges its full faith and credit.

“Guarantee” means a guarantee other than by endorsement of negotiable instruments for collection in the ordinary course of business, direct or indirect, in any manner including, without limitation, by way of a pledge of assets or through letters of credit or reimbursement agreements in respect thereof, of all or any part of any Indebtedness (whether arising by virtue of partnership arrangements, or by agreements to keep-well, to purchase assets, goods, securities or services, to take or pay or to maintain financial statement conditions or otherwise) (other than a Lien of the type described in clause (9) of the definition of Permitted Liens).

“Guarantors” means any Subsidiary of the Company that executes a Note Guarantee in accordance with the provisions of this Indenture, and their respective successors and assigns, in each case, until the Note Guarantee of such Person has been released in accordance with the provisions of this Indenture.

“Hedging Obligations” means, with respect to any specified Person, the obligations of such Person under:

(1)                                  interest rate swap agreements (whether from fixed to floating or from floating to fixed), interest rate cap agreements and interest rate collar agreements;

(2)                                  other agreements or arrangements designed to manage interest rates or interest rate risk; and

(3)                                  other agreements or arrangements designed to protect such Person against fluctuations in currency exchange rates or commodity prices.

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“Holder” means a Person in whose name a Note is registered.

“IAI Global Note” means a Global Note substantially in the form of Exhibit A hereto bearing the Global Note Legend and the Private Placement Legend and deposited with or on behalf of and registered in the name of the Depositary or its nominee that will be issued in a denomination equal to the outstanding principal amount of the Notes sold to Institutional Accredited Investors .

“Immaterial Subsidiary” means, as of any date, any Restricted Subsidiary whose total assets (other than Equity Interests in any other Subsidiary), as of that date, are less than $50.0 million in book value.

“Indebtedness” means, with respect to any specified Person, any indebtedness of such Person (excluding accrued expenses and trade payables), whether or not contingent:

(1)                                  in respect of borrowed money;

(2)                                  evidenced by or issued in exchange for bonds, notes, debentures or similar instruments or letters of credit (or reimbursement agreements in respect thereof) but excluding (i) bid, performance, surety and appeal bonds to the extent such bonds are undrawn upon and (ii) obligations with respect to letters of credit securing obligations (other than obligations described in clauses (1), (4) and (5) entered into in the ordinary course of business of such Person to the extent such letters of credit are not drawn upon or, if and to the extent drawn upon, such drawing is reimbursed within ten business days of payment on such letter of credit;

(3)                                  in respect of banker’s acceptances;

(4)                                  representing Capital Lease Obligations or Attributable Debt in respect of sale and leaseback transactions;

(5)                                  representing the balance deferred and unpaid of the purchase price of any property or services due more than six months after such property is acquired or such services are completed; or

(6)                                  representing any Hedging Obligations,

if and to the extent any of the preceding items (other than letters of credit, Attributable Debt and Hedging Obligations) would appear as a liability upon a balance sheet of the specified Person prepared in accordance with GAAP, but excluding Deemed Capitalized Leases. In addition, the term “Indebtedness” includes all Indebtedness of others secured by a Lien on any asset of the specified Person (whether or not such Indebtedness is assumed by the specified Person) and, to the extent not otherwise included, the Guarantee by the specified Person of any Indebtedness of any other Person. Indebtedness shall be calculated without giving effect to the effects of ASC 815 and related interpretations to the extent such effects would otherwise increase or decrease an amount of Indebtedness for any purpose under this Indenture as a result of accounting for any embedded derivatives created by the terms of such Indebtedness.

Notwithstanding the preceding, “Indebtedness” of a Person shall not include:

(1)                                  any indebtedness that has been defeased in accordance with GAAP or defeased pursuant to the deposit of cash or Cash Equivalents (in an amount sufficient to satisfy all such indebtedness obligations at maturity or redemption, as applicable, and all payments of interest

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and premium, if any) in a trust or account created or pledged for the sole benefit of the holders of such indebtedness, and subject to no other Liens;

(2)                                  any repayment or reimbursement obligation of such Person or any of its Restricted Subsidiaries with respect to Customary Recourse Exceptions, unless and until an event or circumstance occurs that triggers the Person’s or such Restricted Subsidiary’s direct repayment or reimbursement obligation (as opposed to contingent or performance obligations) to the lender or other Person to whom such obligation is actually owed, in which case the amount of such direct payment or reimbursement obligation shall constitute Indebtedness; and

(3)                                  a Lien of the type described in clause (9) of the definition of Permitted Liens.

“Indenture” means this Indenture, as amended or supplemented from time to time.

“Indirect Participant” means a Person who holds a beneficial interest in a Global Note through a Participant.

“Initial Notes” means the first $175.0 million aggregate principal amount of Notes issued under this Indenture on the date hereof.

“Initial Purchasers” means Citigroup Global Markets Inc., Wells Fargo Securities, LLC, Pareto Securities AS, Dougherty & Company, Johnson Rice & Company L.L.C., PNC Capital Markets LLC and Westlake Securities, LLC, with respect to the offer and sale of the Initial Notes and such other initial purchasers party to future purchase agreements entered into in connection with an offer and sale of any Additional Notes.

“INOVA” means INOVA Geophysical Equipment Limited, a limited liability company organized under the laws of the People’s Republic of China or any successor or substitute entity thereof (whether by reincorporation, transfer, merger, amalgamation, conversion or any other entity transaction) in the same or a different jurisdiction and whether known by the same or a different name.

“INOVA Letter of Credit” means that certain letter of credit issued for the account of INOVA Geophysical Equipment Limited in favor of China Merchants Bank Co. Ltd., New York Branch.

“insolvency or liquidation proceeding” means:

(1)                                  any case commenced by or against the Company or any other Guarantor under Title 11, U.S. Code or any similar federal or state law for the relief of debtors, any other proceeding for the reorganization, recapitalization or adjustment or marshalling of the assets or liabilities of the Company or any other Guarantor, any receivership or assignment for the benefit of creditors relating to the Company or any other Guarantor or any similar case or proceeding relative to the Company or any other Guarantor or its creditors, as such, in each case whether or not voluntary;

(2)                                  any liquidation, dissolution, marshalling of assets or liabilities or other winding up of or relating to the Company or any other Guarantor, in each case whether or not voluntary and whether or not involving bankruptcy or insolvency; or

(3)                                  any other proceeding of any type or nature in which substantially all claims of creditors of the Company or any other Guarantor are determined and any payment or distribution is or may be made on account of such claims.

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“Intercreditor Agreement” means the Intercreditor Agreement, substantially in the form attached hereto as Exhibit G, dated as of the date of this Indenture, among the Guarantors, the Priority Lien Credit Agreement Agent, the Priority Lien Collateral Agent, the Trustee and the Collateral Agent, as amended, supplemented or otherwise modified from time to time.

“Institutional Accredited Investor” means an institution that is an “accredited investor” as defined in Rule 501(a)(1), (2), (3) or (7) under the Securities Act, who are not also QIBs.

“Investments” means, with respect to any Person, all direct or indirect investments by such Person in other Persons (including Affiliates) in the forms of loans (including Guarantees or other obligations), advances or capital contributions (excluding commission, travel and similar advances to officers and employees made in the ordinary course of business), purchases or other acquisitions for consideration of Indebtedness, Equity Interests or other securities, together with all items that are or would be classified as investments on a balance sheet prepared in accordance with GAAP. If the Company or any Restricted Subsidiary of the Company sells or otherwise disposes of any Equity Interests of any direct or indirect Restricted Subsidiary of the Company such that, after giving effect to any such sale or disposition, such Person is no longer a Restricted Subsidiary of the Company, the Company will be deemed to have made an Investment on the date of any such sale or disposition equal to the Fair Market Value of the Company’s Investments in such Subsidiary that were not sold or disposed of in an amount determined as provided in Section 4.07(c) hereof. The acquisition by the Company or any Restricted Subsidiary of the Company of a Person that holds an Investment in a third Person will be deemed to be an Investment by the Company or such Restricted Subsidiary in such third Person in an amount equal to the Fair Market Value of the Investments held by the acquired Person in such third Person in an amount determined as provided in Section 4.07(c) hereof. Except as otherwise provided in this Indenture, the amount of an Investment will be determined at the time the Investment is made and without giving effect to subsequent changes in value.

“Legal Holiday” means a Saturday, a Sunday or a day on which banking institutions in the City of New York or at a place of payment are authorized by law, regulation or executive order to remain closed.  If a payment date is a Legal Holiday at a place of payment, payment may be made at that place on the next succeeding day that is not a Legal Holiday, and no interest shall accrue on such payment for the intervening period.

“Letter of Transmittal” means the letter of transmittal to be prepared by the Company and sent to all Holders of the Notes for use by such Holders in connection with an Exchange Offer.

“Lien” means, with respect to any asset, any mortgage, lien, pledge, charge, security interest or encumbrance of any kind in respect of such asset, whether or not filed, recorded or otherwise perfected under applicable law, including any conditional sale or other title retention agreement, any lease in the nature thereof, any option or other agreement to sell or give a security interest in and any filing of or agreement to give any financing statement under the Uniform Commercial Code (or equivalent statutes) of any jurisdiction.

“Lien Release Conditions” means (a) the Discharge of Priority Lien Obligations and (b) the settlement, abandonment or dismissal with prejudice of the WesternGeco L.L.C. vs. ION Geophysical Corporation litigation.

“Lien Sharing and Priority Confirmation” means as to any Series of Priority Lien Debt, the written agreement of the holders of such Series of Priority Lien Debt, as set forth in the credit agreement or other agreement governing such Series of Priority Lien Debt, for the enforceable benefit of all holders

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of Parity Lien Debt, each Parity Lien Representative and each existing and future holder of Permitted Prior Liens:

(1)                                  that all Priority Lien Obligations shall be and are secured equally and ratably by all Priority Liens at any time granted by the Company or any other Guarantor to secure any Obligations in respect of such Series of Priority Lien Debt, whether or not upon property otherwise constituting collateral for such Series of Priority Lien Debt, and that all such Priority Liens will be enforceable by the Priority Lien Collateral Agent for the benefit of all holders of Priority Lien Obligations equally and ratably;

(2)                                  that the holders of Obligations in respect of such Series of Priority Lien Debt are bound by the provisions of the Intercreditor Agreement, including the provisions relating to the ranking of Priority Liens and the order of application of proceeds from enforcement of Priority Liens; and

(3)                                  consenting to and directing the Priority Lien Collateral Agent to perform its obligations under the Intercreditor Agreement and the other Priority Lien Security Documents.

“Moody’s” means Moody’s Investors Service, Inc.

“Net Proceeds” means the aggregate amount of cash proceeds and Cash Equivalents received by the Company or any of its Restricted Subsidiaries in respect of any Asset Sale (including, without limitation, any cash or Cash Equivalents received upon the sale or other disposition of any non-cash consideration received in any Asset Sale but excluding any non-cash consideration deemed to be cash for the purpose of Section 4.10 hereof) net of the direct costs relating to such Asset Sale, including, without limitation, legal, accounting and investment banking fees, and sales commissions, and any relocation expenses incurred as a result of the Asset Sale, taxes paid or payable as a result of the Asset Sale, in each case, after taking into account any available tax credits or deductions and any tax sharing arrangements and amounts required to be applied to the repayment of Indebtedness secured by a Lien on the properties or assets that were the subject of such Asset Sale, or which must by its terms, or in order to obtain a necessary consent to such Asset Sale or by applicable law, be repaid out of the proceeds from such Asset Sale, all distributions and other payments required to be made to minority interest holders in Restricted Subsidiaries or joint ventures as a result of such Asset Sale, and any reserve for adjustment or indemnification obligations in respect of the sale price of such asset or assets established in accordance with GAAP.

“Non-Recourse Debt” means Indebtedness:

(1)                                  as to which neither the Company nor any of its Restricted Subsidiaries (a) provides credit support of any kind (including any undertaking, agreement or instrument that would constitute Indebtedness) or (b) is directly or indirectly liable as a guarantor or otherwise, except for Customary Recourse Exceptions;

(2)                                  as to which the lenders have been notified in writing that they will not have any recourse to the stock or assets of the Company or any of its Restricted Subsidiaries (other than as permitted in clause (3) below); and

(3)                                  as to which the lenders have been notified in writing that they will not have any recourse to the Capital Stock or assets of the Company or any of its Restricted Subsidiaries except (a) as contemplated by clause (9) of the definition of Permitted Liens and (b) except for Customary Recourse Exceptions.

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“Non-U.S. Person” means a Person who is not a U.S. Person.

“Note Documents” means this Indenture, the Notes and the Security Documents.

“Note Guarantee” means the Guarantee by each Guarantor of the Company’s obligations under this Indenture and the Notes, executed pursuant to the provisions of this Indenture.

“Notes” has the meaning assigned to it in the preamble to this Indenture.  The Initial Notes and the Additional Notes shall be treated as a single class for all purposes under this Indenture, including for purposes of waivers, amendments, redemptions and offers to purchase, and unless the context otherwise requires, all references to the Notes shall include the Initial Notes and any Additional Notes.

“Obligations” means any principal (including reimbursement obligations with respect to letters of credit whether or not drawn), interest (including, to the extent legally permitted, all interest accrued thereon after the commencement of any insolvency or liquidation proceeding at the rate, including any applicable post-default rate, specified in the Priority Lien Documents, even if such interest is not enforceable, allowable or allowed as a claim in such proceeding), premium (if any), fees, indemnifications, reimbursements, expenses and other liabilities payable under the documentation governing any Indebtedness.

“Officer” means, with respect to any Person, the Chairman of the Board, the Chief Executive Officer, the President, the Chief Operating Officer, the Chief Financial Officer, the Chief Accounting Officer, the Treasurer, any Assistant Treasurer, the Controller, the Secretary, any Assistant Secretary or any Vice President of such Person (or, if such Person is a limited partnership, the Chairman of the Board, the Chief Executive Officer, the President, the Chief Operating Officer, the Chief Financial Officer, the Chief Accounting Officer, the Treasurer, any Assistant Treasurer, the Controller, the Secretary, any Assistant Secretary or any Vice President of such Person’s general partner).

“Officers’ Certificate” means a certificate signed on behalf of the Company by two Officers of the Company, one of whom must be the principal executive officer, the principal financial officer, the treasurer or the principal accounting officer of the Company, that meets the requirements of Section 13.05 hereof.

“Opinion of Counsel” means a written opinion from legal counsel who is reasonably acceptable to the Trustee or the Collateral Agent, as applicable, that meets the requirements of Section 13.05 hereof.  The counsel may be an employee of or counsel to the Company.

“Parity Lien” means a Lien granted by a Security Document to the Collateral Agent for the benefit of the Parity Lien Secured Parties, at any time, upon any property of the Company or any other Guarantor to secure Parity Lien Obligations.

“Parity Lien Debt” means the Notes issued on the date of this Indenture and any Additional Notes, if any, incurred under Section 4.09(b)(iii) (in each case, including any related Exchange Notes).

“Parity Lien Documents” means, collectively, the Note Documents and the Security Documents (other than any security documents that do not secure Parity Lien Obligations).

“Parity Lien Obligations” means Parity Lien Debt and all other Obligations in respect thereof.

“Parity Lien Representative” means the Trustee.

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“Parity Lien Secured Party” means the Holders of the Notes and the Trustee.

“Participant” means, with respect to the Depositary, Euroclear or Clearstream, a Person who has an account with the Depositary, Euroclear or Clearstream, respectively (and, with respect to DTC, shall include Euroclear and Clearstream).

“Permitted Acquisition Indebtedness” means Indebtedness or Disqualified Stock of the Company or any of its Restricted Subsidiaries to the extent such Indebtedness or Disqualified Stock was Indebtedness or Disqualified Stock of any other Person existing at the time (a) such Person became a Restricted Subsidiary of the Company or (b) such Person was merged or consolidated with or into the Company or any of its Restricted Subsidiaries or (c) assets of such Person were acquired by the Company or any of its Restricted Subsidiaries and such Indebtedness was assumed in connection therewith (excluding any such Indebtedness that is repaid contemporaneously with such event); provided that on the date such Person became a Restricted Subsidiary of the Company or the date such Person was merged or consolidated with or into the Company or any of its Restricted Subsidiaries or on the date of such asset acquisition, as applicable, either:

(1)                                  immediately after giving effect to such transaction on a pro forma basis as if the same had occurred at the beginning of the applicable four-quarter period, the Company or such Restricted Subsidiary, as applicable, would be permitted to incur at least $1.00 of additional Indebtedness pursuant to the Fixed Charge Coverage Ratio test set forth in Section 4.09(a) hereof, or

(2)                                  immediately after giving effect to such transaction on a pro forma basis as if the same had occurred at the beginning of the applicable four-quarter period, the Fixed Charge Coverage Ratio of the Company would be equal to or greater than the Fixed Charge Coverage Ratio of the Company immediately prior to such transaction.

“Permitted Business” means any business that is the same as, or reasonably related, ancillary or complementary to, any of the businesses in which the Company and its Restricted Subsidiaries are engaged on the date of this Indenture.

“Permitted Investments” means:

(1)                                  any Investment in the Company or in a Restricted Subsidiary of the Company;

(2)                                  any Investment in Cash Equivalents;

(3)                                  any Investment by the Company or any Restricted Subsidiary of the Company in a Person, if as a result of such Investment:

(a)                                  such Person becomes a Restricted Subsidiary of the Company; or

(b)                                  such Person is merged, consolidated or amalgamated with or into, or transfers or conveys substantially all of its assets to, or is liquidated into, the Company or a Restricted Subsidiary of the Company;

(4)                                  any Investment made as a result of the receipt of non-cash consideration from an Asset Sale that was made pursuant to and in compliance with Section 4.10 hereof;

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(5)                                  an acquisition of assets or Capital Stock in any Person solely in exchange for the issuance of Equity Interests (other than Disqualified Stock) of the Company;

(6)                                  any Investments received in compromise or resolution of (a) obligations of trade creditors or customers that were incurred in the ordinary course of business of the Company or any of its Restricted Subsidiaries, including pursuant to any plan of reorganization or similar arrangement upon the bankruptcy or insolvency of any trade creditor or customer or (b) litigation, arbitration or other disputes;

(7)                                  Investments represented by Hedging Obligations;

(8)                                  loans or advances to employees made in the ordinary course of business of the Company or any Restricted Subsidiary of the Company in an aggregate principal amount not to exceed $5.0 million at any one time outstanding;

(9)                                  Investments in any Person to the extent such Investments consist of prepaid expenses, negotiable instruments held for collection and lease, utility and workers’ compensation, performance and other similar deposits made in the ordinary course of business by the Company or any of its Restricted Subsidiaries;

(10)                           any guarantee of Indebtedness permitted to be incurred by Section 4.09 hereof other than a guarantee of Indebtedness of an Affiliate of the Company that is not a Restricted Subsidiary of the Company;

(11)                           any Investment existing on, or made pursuant to binding commitments existing on, the date of this Indenture and any Investment consisting of an extension, modification or renewal of any Investment existing on, or made pursuant to a binding commitment existing on, the date of this Indenture; provided that the amount of any such Investment may be increased (a) as required by the terms of such Investment as in existence on the date of this Indenture or (b) as otherwise permitted under this Indenture;

(12)                           Investments acquired after the date of this Indenture as a result of the acquisition by the Company or any Restricted Subsidiary of the Company of another Person, including by way of a merger, amalgamation or consolidation with or into the Company or any of its Restricted Subsidiaries, or all or substantially all of the assets of another Person, in each case, in a transaction that is not prohibited by Section 5.01 hereof after the date of this Indenture to the extent that such Investments were not made in contemplation of such acquisition, merger, amalgamation or consolidation and were in existence on the date of such acquisition, merger, amalgamation or consolidation;

(15)                           Investments in INOVA and/or the Seabed J.V. having an aggregate Fair Market Value (measured on the date each such Investment was made and without giving effect to subsequent changes in value), when taken together with all other Investments made pursuant to this clause (15) that are at the time outstanding, not to exceed the sum of (a) $60.0 million and (b) the gross profits realized by the Company or any Restricted Subsidiary from services provided or products sold to INOVA and/or the Seabed J.V., since the date of this Indenture;

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(16)                           the Investments described in the “Use of Proceeds” section of the Company’s Offering Memorandum dated May 8, 2013, relating to the initial offering of the Notes; and

(17)                           other Investments in any Person having an aggregate Fair Market Value (measured on the date each such Investment was made and without giving effect to subsequent changes in value), when taken together with all other Investments made pursuant to this clause (17) that are at the time outstanding not to exceed the greater of (a) $25.0 million and (b) and amount equal to 10.0% of the Company’s Consolidated Net Tangible Assets determined at the time of such Investment this clause) (after giving effect to any dividends, interest payments, return of capital and subsequent reduction in the amount of any Investments made pursuant to this clause as a result of the repayment or other disposition thereof, in an amount not to exceed the amount of such Investments previously made pursuant to in this clause); provided , however , that if any Investment pursuant to this clause (17) is made in any Person that is not a Restricted Subsidiary of the Company at the date of the making of such Investment and such Person becomes a Restricted Subsidiary of the Company after such date, such Investment shall thereafter be deemed to have been made pursuant to clause (1) above and shall cease to have been made pursuant to this clause (17) for so long as such Person continues to be a Restricted Subsidiary.

With respect to any Permitted Investment, the Company may, in its sole discretion, allocate all or any portion of any Permitted Investment and later re-allocate all or any portion of any Permitted Investment to one or more of the above clauses (1) through (17) so that the entire Permitted Investment would be a Permitted Investment. Amounts permitted under clauses (15), (16) and (17) shall be measured after giving effect to any dividends, interest payments, return of capital and subsequent reduction in the amount of any Permitted Investment made pursuant to such clause as a result of the repayment or other disposition thereof, in an amount not to exceed the amount of such Permitted Investment previously made pursuant to such clause.

“Permitted Joint Venture” means any entity characterized as a joint venture, however structured, engaged in a Permitted Business in which the Company or any Restricted Subsidiary has an ownership interest; provided that such joint venture is not a Subsidiary of the Company.

“Permitted Liens” means:

(1)                                  Liens held by the Priority Lien Collateral Agent securing (a) Priority Lien Debt in an aggregate principal amount not exceeding the Priority Lien Cap and (b) all related Priority Lien Obligations;

(2)                                  Liens to secure the Notes and the Note Guarantees issued on the date of this Indenture and any obligations owing to the Trustee or the Collateral Agent under this Indenture, the Security Documents or the Intercreditor Agreement in connection therewith;

(3)                                  Liens to secure Hedging Obligations so long as such Hedging Obligations are permitted to be incurred under this Indenture;

(4)                                  Liens on property of a Person existing at the time such Person becomes a Restricted Subsidiary of the Company or is merged with or into or consolidated with the Company or any Restricted Subsidiary of the Company; provided that such Liens were in existence prior to the contemplation of such Person becoming a Restricted Subsidiary of the Company or such merger or consolidation and do not extend to any assets other than those of the Person that becomes a Restricted Subsidiary of the Company or is merged with or into or

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consolidated with the Company or any Restricted Subsidiary of the Company (plus improvements and accessions to such property or proceeds or distributions thereof);

(5)                                  Liens on property (including Capital Stock) existing at the time of acquisition of the property by the Company or any Subsidiary of the Company; provided that such Liens were in existence prior to such acquisition and not incurred in contemplation of, such acquisition;

(6)                                  Liens on cash and Cash Equivalents to secure the performance of statutory obligations, insurance, surety or appeal bonds, workers compensation obligations, performance bonds or other obligations of a like nature incurred in the ordinary course of business (including Liens to secure letters of credit issued to assure payment of such obligations) and including any bonds issued in connection with the WesternGeco L.L.C. vs. ION Geophysical Corporation litigation;

(7)                                  Liens to secure Indebtedness (including Capital Lease Obligations) permitted by Section 4.09(b)(iv) hereof covering only the assets acquired with or financed by such Indebtedness (plus improvements and accessions to such property or proceeds or distributions thereof);

(8)                                  Liens to secure Indebtedness of Foreign Subsidiaries permitted to be incurred under this Indenture, to the extent such Liens relate only to assets and properties of Foreign Subsidiaries;

(9)                                  Liens on the Capital Stock of any Unrestricted Subsidiary or any Permitted Joint Venture granted by the Company or any Restricted Subsidiary to the extent securing Non-Recourse Debt of such Unrestricted Subsidiary or Permitted Joint Venture;

(10)                           Liens existing on the date of this Indenture, other than Liens securing Indebtedness and other obligations incurred pursuant to Section 4.09(b)(i) hereof;

(11)                           Liens for taxes, assessments or governmental charges or claims that are not yet delinquent by more than 60 days or that are being contested in good faith by appropriate proceedings promptly instituted and diligently concluded; provided that any reserve or other appropriate provision as is required in conformity with GAAP has been made therefor;

(12)                           Liens imposed by law, such as carriers’, warehousemen’s, landlord’s and mechanics’ Liens, in each case, incurred in the ordinary course of business;

(13)                           survey exceptions, easements or reservations of, or rights of others for, licenses, rights-of-way, sewers, electric lines, telegraph and telephone lines and other similar purposes, or zoning or other restrictions as to the use of real property that were not incurred in connection with Indebtedness and that do not in the aggregate materially adversely affect the value of said properties or materially impair their use in the operation of the business of such Person;

(14)                           Liens created for the benefit of (or to secure) the Notes or the Note Guarantees;

(15)                           Liens to secure any Permitted Refinancing Indebtedness permitted to be incurred under this Indenture; provided, however, that:

(a)                                  the new Lien is limited to all or part of the same property and assets that secured or, under the written agreements pursuant to which the original Lien arose, could

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secure the original Lien (plus improvements and accessions to, such property or proceeds or distributions thereof); and

(b)                                  the Indebtedness secured by the new Lien is not increased to any amount greater than the sum of (x) the outstanding principal amount, or, if greater, committed amount, of the Indebtedness renewed, refunded, refinanced, replaced, defeased or discharged with such Permitted Refinancing Indebtedness and (y) an amount necessary to pay any fees and expenses, including premiums, related to such renewal, refunding, refinancing, replacement, defeasance or discharge;

(16)                           Liens on insurance policies and proceeds thereof, or other deposits, to secure insurance premium financings;

(17)                           filing of Uniform Commercial Code financing statements as a precautionary measure in connection with operating leases;

(18)                           bankers’ Liens, rights of setoff, Liens arising out of judgments or awards not constituting an Event of Default and notices of lis pendens and associated rights related to litigation being contested in good faith by appropriate proceedings and for which adequate reserves have been made;

(19)                           Liens on cash, Cash Equivalents or other property arising in connection with the defeasance, discharge or redemption of Indebtedness;

(20)                           Liens on specific items of inventory or other goods (and the proceeds thereof) of any Person securing such Person’s obligations in respect of bankers’ acceptances issued or created in the ordinary course of business for the account of such Person to facilitate the purchase, shipment or storage of such inventory or other goods;

(21)                           grants of software and other technology and intellectual property licenses in the ordinary course of business;

(22)                           Liens arising out of conditional sale, title retention, consignment or similar arrangements for the sale of goods entered into in the ordinary course of business;

(23)                           Liens in favor of customs and revenue authorities arising as a matter of law to secure payment of customs duties in connection with the importation of goods;

(24)                           Liens in favor of the Company or any of the Guarantors;

(25)                           Liens on cash collateral or Cash Equivalents for letters of credit and/or bank guarantees permitted under Section 4.09(b)(xx) hereof, not to exceed 105% of the face amount thereof; provided that the aggregate book value of the assets encumbered by all Liens permitted by this clause (25) shall not exceed $10.0 million in the aggregate at any one time outstanding;

(26)                           Liens arising under this Indenture in favor of the Trustee for its own benefit and similar Lien in favor of other trustees, agents and representatives arising under instruments governing Indebtedness permitted to be incurred under this Indenture; provided , however , that such Liens are solely for the benefit of the trustees, agents or representatives in their capacities as such and not for the benefit of the holders of such Indebtedness;

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(27)                           Liens to secure Parity Lien Debt permitted to be incurred under Section 4.09(b)(iii) hereof; and

(28)                           Liens to secure Parity Lien Debt permitted to be incurred under Section 4.09 hereof in an amount not to exceed $15.0 million at any one time outstanding.

“Permitted Prior Liens” means:

(1)                                  Liens described in clause (1) of the definition of “Permitted Liens;”

(2)                                  Liens described in clauses (4), (5), (7), (10), (16), (18), (19), (20) and (26) of the definition of “Permitted Liens;” and

(3)                                  Permitted Liens that arise by operation of law and are not voluntarily granted, to the extent entitled by law to priority over the Liens created by the Priority Lien Security Documents or the Security Documents.

“Permitted Refinancing Indebtedness” means any Indebtedness of the Company or any of its Restricted Subsidiaries or any Disqualified Stock of the Company incurred or issued in exchange for, or the net proceeds of which are used to extend, refinance, renew, replace, defease, discharge, refund or otherwise retire for value, in whole or in part, any other Indebtedness of the Company or any of its Restricted Subsidiaries (other than intercompany Indebtedness) or any Disqualified Stock of the Company (the “Refinanced Indebtedness” ), provided that:

(1)                                  the principal amount, or in the case of Disqualified Stock, the amount thereof as determined in accordance with the definition of Disqualified Stock, of such Permitted Refinancing Indebtedness does not exceed the principal amount of the Refinanced Indebtedness (plus all accrued and unpaid interest on or accrued and unpaid dividends on the Refinanced Indebtedness, as the case may be, and the amount of all fees, expenses and premiums incurred in connection therewith) (or, if such Permitted Refinancing Indebtedness refinances Indebtedness under a revolving credit facility or other agreement providing for a commitment for subsequent borrowings, with a maximum commitment not to exceed the maximum commitment under such revolving credit facility or other agreement);

(2)                                  such Permitted Refinancing Indebtedness has a final maturity date or redemption date, as applicable, later than or equal to the shorter of (a) 91 days following the Stated Maturity or (b) the final maturity or redemption date as applicable, of the Refinanced Indebtedness;

(3)                                  such Permitted Refinancing Indebtedness has a Weighted Average Life to Maturity at the time such Permitted Refinancing Indebtedness is incurred that is no shorter than the Weighted Average Life to Maturity of the portion of the Indebtedness being renewed, refunded, refinanced, replaced, defeased or discharged;

(4)                                  if the Refinanced Indebtedness is contractually subordinated or otherwise junior in right of payment to the Notes or the Subsidiary Guarantees, such Permitted Refinancing Indebtedness is contractually subordinated or otherwise junior in right of payment to the Notes or the Subsidiary Guarantees on terms at least as favorable to the Holders of Notes as those contained in the documentation governing the Refinanced Indebtedness;

(5)                                  such Indebtedness is incurred either by the Company or by the Restricted Subsidiary of the Company that was the obligor on the Indebtedness being renewed, refunded,

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refinanced, replaced, defeased or discharged and is guaranteed only by Persons who were obligors on the Indebtedness being renewed, refunded, refinanced, replaced, defeased or discharged (or by any Person that was required by the documents governing such Indebtedness to guarantee such Indebtedness); and

(6)                                  the proceeds of the Permitted Refinancing Indebtedness shall be used substantially concurrently with the incurrence thereof to redeem, refinance, replace, defease, discharge, refund or otherwise retire for value the Refinanced Indebtedness, unless the Refinanced Indebtedness is not then due and is not redeemable or prepayable at the option of the obligor thereof or is redeemable or prepayable only with notice, in which case such proceeds shall be held in a segregated account of the obligor of the Refinanced Indebtedness until the Refinanced Indebtedness becomes due or redeemable or prepayable or such notice period lapses and then shall be used to refinance the Refinanced Indebtedness; provided that in any event the Refinanced Indebtedness shall be redeemed, refinanced replaced, defeased, discharged, refunded or otherwise retired for value within 120 days of the incurrence of the Permitted Refinancing Indebtedness.

Notwithstanding the foregoing, any indebtedness incurred under Credit Facilities shall be subject to the refinancing provision of the definition of Credit Facilities and not pursuant to the requirements set forth in this definition of Permitted Refinancing Indebtedness.

“Person” means any individual, corporation, partnership, joint venture, association, joint-stock company, trust, unincorporated organization, limited liability company or government or other entity.

“Priority Lien” means a Lien granted by a Priority Lien Security Document to the Priority Lien Collateral Agent, at any time, upon any property of the Company or any other Guarantor to secure Priority Lien Obligations.

“Priority Lien Cap” means, as of any date, the principal amount outstanding under the Credit Agreement and/or the Indebtedness outstanding under any other Credit Facility, in an aggregate principal amount not to exceed the sum of the amount provided by clause (1) of the definition of Permitted Debt, as of any date, less the amount of Parity Lien Debt incurred after the date of this Indenture the net proceeds of which are used to repay Priority Lien Debt. For purposes of this definition, all letters of credit will be valued at the face amount thereof, whether or not drawn and all Hedging Obligations will be valued at zero.

“Priority Lien Collateral Agent” means China Merchants Bank Co. Ltd., New York Branch, in its capacity as collateral agent under the Priority Lien Security Documents, together with its successors in such capacity.

“Priority Lien Debt” means:

(1)                                  Indebtedness of the Company under the Credit Agreement that was permitted to be incurred and secured under each applicable Secured Debt Document (or as to which the lenders under the Credit Agreement obtained an Officers’ Certificate at the time of incurrence to the effect that such Indebtedness was permitted to be incurred and secured by all applicable Secured Debt Documents);

(2)                                  Indebtedness of the Company under any other Credit Facility that is secured equally and ratably with the Credit Agreement by a Priority Lien that was permitted to be

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incurred and so secured under each applicable Secured Debt Document; provided , in the case of any Indebtedness referred to in this clause (2), that:

(a)                                  on or before the date on which such Indebtedness is incurred by the Company, such Indebtedness is designated by the Company, in an Officers’ Certificate delivered to each Priority Lien Representative, the Priority Lien Collateral Agent and the Collateral Agent, as “Priority Lien Debt” for the purposes of the Secured Debt Documents; provided that no Series of Secured Debt may be designated as both Parity Lien Debt and Priority Lien Debt;

(b)                                  such Indebtedness is governed by a credit agreement or other agreement that includes a Lien Sharing and Priority Confirmation; and

(c)                                   all requirements set forth in the Intercreditor Agreement as to the confirmation, grant or perfection of the Priority Lien Collateral Agent’s Lien to secure such Indebtedness or Obligations in respect thereof are satisfied (and the satisfaction of such requirements and the other provisions of this clause (c) will be conclusively established if the Company delivers to the Priority Lien Collateral Agent and the Collateral Agent an Officers’ Certificate stating that such requirements and other provisions have been satisfied and that such Indebtedness is “Priority Lien Debt”); and

(3)                                  Hedging Obligations of the Company incurred to hedge or manage interest rate risk with respect to Priority Lien Debt; provided that:

(a)                                  such Hedging Obligations are secured by a Priority Lien on all of the assets and properties that secure Indebtedness under the Credit Facility in respect of which such Hedging Obligations are incurred; and

(b)                                  such Priority Lien is senior to or on a parity with the Priority Liens securing Indebtedness under the Credit Facility in respect of which such Hedging Obligations are incurred.

“Priority Lien Documents” means the Credit Agreement and any other Credit Facility pursuant to which any Priority Lien Debt is incurred and the Priority Lien Security Documents.

“Priority Lien Obligations” means the Priority Lien Debt and all other Obligations in respect of Priority Lien Debt, including without limitation the “Secured Obligations” as such term is defined in the Existing Priority Lien Security Agreement as of the date of this Indenture.

“Priority Lien Representative” means (1) the Credit Agreement Agent or (2) in the case of any other Series of Priority Lien Debt, the trustee, agent or representative of the holders of such Series of Priority Lien Debt who maintains the transfer register for such Series of Priority Lien Debt and is appointed as a representative of the Priority Lien Debt (for purposes related to the administration of the Priority Lien Security Documents) pursuant to the credit agreement or other agreement governing such Series of Priority Lien Debt and who has become a party to the Intercreditor Agreement by executing a joinder in the form required under the Intercreditor Agreement.

“Priority Lien Security Documents” means the Intercreditor Agreement, each Lien Sharing and Priority Confirmation, and all security documents, pledge agreements, collateral assignments, mortgages, deeds of trust, collateral agency agreements, control agreements or other grants or transfers for security executed and delivered by the Company or any other Guarantor creating (or purporting to create) a

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Priority Lien upon collateral in favor of the Priority Lien Collateral Agent, in each case, as amended, modified, renewed, restated or replaced, in whole or in part, from time to time, in accordance with its terms.

“Priority Lien Secured Parties” means the “Secured Parties” as defined in the Priority Lien Documents.

“Private Placement Legend” means the legend set forth in Section 2.06(g)(i) hereof to be placed on all Notes issued under this Indenture except where otherwise permitted by the provisions of this Indenture.

“QIB” means a “qualified institutional buyer” as defined in Rule 144A.

“Registration Rights Agreement” means the Registration Rights Agreement, dated as of May 13, 2013, among the Company, the Guarantors and the other parties named on the signature pages thereof, as such agreement may be amended, modified or supplemented from time to time, and, with respect to any Additional Notes, one or more registration rights agreements among the Company, the Guarantors and the other parties thereto, as such agreement(s) may be amended, modified or supplemented from time to time, relating to rights given by the Company to the purchasers of Additional Notes to register such Additional Notes under the Securities Act.

“Regulation S” means Regulation S promulgated under the Securities Act.

“Regulation S Global Note” means a Global Note substantially in the form of Exhibit A hereto bearing the Global Note Legend and the Private Placement Legend and deposited with or on behalf of and registered in the name of the Depositary or its nominee, issued in a denomination equal to the outstanding principal amount of the Notes sold in reliance on Rule 903 of Regulation S.

“ Reporting Default ” means the failure by the Company for 180 days after notice from the Trustee or Holders of at least 25% in aggregate principal amount of the Notes then outstanding to comply with the provisions described in Section 4.03 hereof.

“Responsible Officer,” when used with respect to the Trustee, means any officer within the Corporate Trust Administration of the Trustee (or any successor group of the Trustee) or any other officer of the Trustee customarily performing functions similar to those performed by any of the above designated officers and also means, with respect to a particular corporate trust matter, any other officer to whom such matter is referred because of his knowledge of and familiarity with the particular subject, and who, in each case, shall have direct responsibility for the administration of this Indenture.

“Restricted Definitive Note” means a Definitive Note bearing the Private Placement Legend.

“Restricted Global Note” means a Global Note bearing the Private Placement Legend.

“Restricted Investment” means an Investment other than a Permitted Investment.

“Restricted Period” means the 40-day distribution compliance period as defined in Regulation S.

“ Restricted Subsidiary ” of a Person means any Subsidiary of the referent Person that is not an Unrestricted Subsidiary.

“Rule 144” means Rule 144 promulgated under the Securities Act.

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“Rule 144A” means Rule 144A promulgated under the Securities Act.

“Rule 903” means Rule 903 promulgated under the Securities Act.

“Rule 904” means Rule 904 promulgated under the Securities Act.

“S&P” means Standard & Poor’s Ratings Group.

“Sale of Collateral” means any Asset Sale involving a sale or other disposition of Collateral.

“Seabed J.V.” means GeoRXT B.V., a Netherlands entity, or any successor or substitute entity thereof (whether by reincorporation, transfer, merger, amalgamation, conversion or any other entity transaction) in the same or a different jurisdiction and whether known by the same or a different name.

“SEC” means the Securities and Exchange Commission.

“Secured Debt” means Parity Lien Debt and Priority Lien Debt.

“Secured Debt Documents” means the Parity Lien Documents and the Priority Lien Documents.

“Secured Debt Representative” means the Parity Lien Representative and each Priority Lien Representative.

“Secured Obligations” means Parity Lien Obligations and Priority Lien Obligations.

“Securities Act” means the Securities Act of 1933, as amended.

“Security Documents” means the Intercreditor Agreement, each Lien Sharing and Priority Confirmation, and all security documents, pledge agreements, collateral assignments, mortgages, deeds of trust, collateral agency agreements, control agreements or other grants or transfers for security executed and delivered by the Company or any Guarantor creating (or purporting to create) a Parity Lien upon Collateral in favor of the Collateral Agent for the benefit of the Parity Lien Secured Parties, in each case, as amended, modified, renewed, restated or replaced, in whole or in part, from time to time, in accordance with its terms and the provisions described in Section 5.3 of the Intercreditor Agreement.

“Series D Preferred Stock” means shares of the Company’s (a) Series D-1 Cumulative Convertible Preferred Stock, the terms of which are governed by that certain Certificate of Rights and Preferences of Series D-1 Cumulative Convertible Preferred Stock of Input/Output, Inc., dated February 16, 2005, and (b) Series D-2 Cumulative Convertible Preferred Stock, the terms of which are governed by that certain Certificate of Rights and Preferences of Series D-2 Cumulative Convertible Preferred Stock of ION Geophysical Corporation, dated December 6, 2007, that are outstanding as of the date of this Indenture.

“Series of Priority Lien Debt” means, severally, the Indebtedness outstanding under the Credit Agreement and any other Credit Facility that constitutes Priority Lien Debt.

“Series of Secured Debt” means Parity Lien Debt and each Series of Priority Lien Debt.

“Shelf Registration Statement” means a Shelf Registration Statement as defined in the applicable Registration Rights Agreement.

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“Significant Subsidiary” means any Restricted Subsidiary that would be a “significant subsidiary” as defined in Article 1, Rule 1-02 of Regulation S-X under the Securities Act, as such Regulation is in effect on the date of this Indenture.

“Special Interest” has the meaning assigned to that term pursuant to the applicable Registration Rights Agreement.

“Stated Maturity” means, with respect to any installment of interest or principal on any series of Indebtedness, the date on which the payment of interest or principal was scheduled to be paid in the documentation governing such Indebtedness as of the first date it was incurred in compliance with the terms of this Indenture, and shall not include any contingent obligations to repay, redeem or repurchase any such interest or principal prior to the date originally scheduled for the payment thereof; provided that, in the case of debt securities that are by their terms convertible into Capital Stock (or cash or a combination of cash and Capital Stock based on the value of the Capital Stock) of the Company, any obligation to offer to repurchase such debt securities on a date(s) specified in the original terms of such securities, which obligation is not subject to any condition or contingency, will be treated as a Stated Maturity date of such convertible debt securities.

“Subsidiary” means, with respect to any specified Person:

(1)                                  any corporation, association or other business entity of which more than 50% of the total voting power of shares of Capital Stock entitled (without regard to the occurrence of any contingency and after giving effect to any voting agreement or stockholders’ agreement that effectively transfers voting power) to vote in the election of directors, managers or trustees of the corporation, association or other business entity is at the time owned or controlled, directly or indirectly, by that Person or one or more of the other Subsidiaries of that Person (or a combination thereof); and

(2)                                  any partnership or limited liability company of which (a) more than 50% of the capital accounts, distribution rights, total equity and voting interests or general and limited partnership interests, as applicable, are owned or controlled, directly or indirectly, by such Person or one or more of the other Subsidiaries of that Person or a combination thereof, whether in the form of membership, general, special or limited partnership interests or otherwise, and (b) such Person or any Subsidiary of such Person is a controlling general partner or otherwise controls such entity.

“TIA” means the Trust Indenture Act of 1939, as amended (15 U.S.C. §§ 77aaa-77bbbb).

“Treasury Rate” means, as of any redemption date, the yield to maturity as of the earlier of (a) such redemption date or (b) the date on which such Notes are defeased or satisfied and discharged, of the most recently issued United States Treasury securities with a constant maturity (as compiled and published in the most recent Federal Reserve Statistical Release H.15 (519) that has become publicly available at least two business days prior to such date (or, if such Statistical Release is no longer published, any publicly available source of similar market data)) most nearly equal to the period from the redemption date to May 15, 2015; provided, however , that if the period from the redemption date to May 15, 2015, is less than one year, the weekly average yield on actually traded United States Treasury securities adjusted to a constant maturity of one year will be used. Any such Treasury Rate shall be obtained by the Company.

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“Trustee” means Wilmington Trust, National Association, in its capacity as trustee, until a successor replaces it in accordance with the applicable provisions of this Indenture and thereafter means the successor serving hereunder.

“Unrestricted Definitive Note” means a Definitive Note that does not bear and is not required to bear the Private Placement Legend.

“Unrestricted Global Note” means a Global Note that does not bear and is not required to bear the Private Placement Legend.

“Unrestricted Subsidiary” means any Subsidiary of the Company that is designated by the Board of Directors of the Company as an Unrestricted Subsidiary pursuant to a resolution of the Board of Directors, but only to the extent that such Subsidiary:

(1)                                  has no Indebtedness other than Non-Recourse Debt;

(2)                                  except as permitted by Section 4.11 hereof, is not party to any agreement, contract, arrangement or understanding with the Company or any Restricted Subsidiary of the Company unless the terms of any such agreement, contract, arrangement or understanding are no less favorable to the Company or such Restricted Subsidiary than those that might be obtained at the time from Persons who are not Affiliates of the Company;

(3)                                  is a Person with respect to which neither the Company nor any of its Restricted Subsidiaries has any direct or indirect obligation (a) to subscribe for additional Equity Interests or (b) to maintain or preserve such Person’s financial condition or to cause such Person to achieve any specified levels of operating results; and

(4)                                  has not guaranteed or otherwise directly or indirectly provided credit support for any Indebtedness of the Company or any of its Restricted Subsidiaries (except (a) to the extent such guarantee or credit support would be released upon such designation and (b) for Liens of the type described in clause (9) of the definition of Permitted Liens).

All Subsidiaries of an Unrestricted Subsidiary shall also be Unrestricted Subsidiaries.

“U.S. Person” means a U.S. Person as defined in Rule 902(k) promulgated under the Securities Act.

“Voting Stock” of any specified Person as of any date means the Capital Stock of such Person entitling the holder thereof (whether at all time or only so long as no senior class of Capital Stock has voting power by reason of any contingency) that is at the time entitled to vote in the election of the Board of Directors of such Person.

“Weighted Average Life to Maturity” means, when applied to any Indebtedness at any date, the number of years obtained by dividing:

(1)                                  the sum of the products obtained by multiplying (a) the amount of each then remaining installment, sinking fund, serial maturity or other required payments of principal, including payment at final maturity, in respect of the Indebtedness, by (b) the number of years (calculated to the nearest one-twelfth) that will elapse between such date and the making of such payment; by

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(2)                                  the then outstanding principal amount of such Indebtedness.

Section 1.03                              Incorporation by Reference of Trust Indenture Act .

Whenever this Indenture refers to a provision of the TIA, the provision is incorporated by reference in and made a part of this Indenture.

The following TIA terms used in this Indenture have the following meanings:

“indenture securities” means the Notes;

“indenture security Holder” means a Holder of a Note;

“indenture to be qualified” means this Indenture;

“indenture trustee” or “institutional trustee” means the Trustee; and

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“obligor” on the Notes and the Note Guarantees means the Company and the Guarantors, respectively, and any successor obligor upon the Notes and the Note Guarantees, respectively.

All other terms used in this Indenture that are defined by the TIA, defined by TIA reference to another statute or defined by SEC rule under the TIA have the meanings so assigned to them.

Section 1.04                              Rules of Construction .

Unless the context otherwise requires:

(i)                                      a term has the meaning assigned to it;

(ii)                                   an accounting term not otherwise defined has the meaning assigned to it in accordance with GAAP;

(iii)                                “or” is not exclusive;

(iv)                               “including” is not limiting;

(v)                                  words in the singular include the plural, and in the plural include the singular;

(vi)                               “will” shall be interpreted to express a command;

(vii)                            provisions apply to successive events and transactions; and

(viii)                         references to sections of or rules under the Securities Act will be deemed to include substitute, replacement of successor sections or rules adopted by the SEC from time to time.

ARTICLE 2
THE NOTES

Section 2.01                              Form and Dating .

(a)                                  General .  The Notes and the Trustee’s certificate of authentication will be substantially in the form of Exhibit A hereto.  The Notes may have notations, legends or endorsements required by law, stock exchange rule or usage.  Each Note will be dated the date of its authentication.  The Notes shall be in minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof.

The terms and provisions contained in the Notes will constitute, and are hereby expressly made, a part of this Indenture and the Company, the Guarantors and the Trustee, by their execution and delivery of this Indenture, expressly agree to such terms and provisions and to be bound thereby.  However, to the extent any provision of any Note conflicts with the express provisions of this Indenture, the provisions of this Indenture shall govern and be controlling.

(b)                                  Global Notes .  Notes issued in global form will be substantially in the form of Exhibit A hereto (including the Global Note Legend thereon and the “Schedule of Exchanges of Interests in the Global Note” attached thereto).  Notes issued in definitive form will be substantially in the form of Exhibit A hereto (but without the Global Note Legend thereon and without the “Schedule of Exchanges of Interests in the Global Note” attached thereto).  Each Global Note will represent such of the outstanding Notes as will be specified therein and each shall provide that it represents the aggregate principal amount of outstanding Notes from time to time endorsed thereon and that the aggregate principal amount of

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outstanding Notes represented thereby may from time to time be reduced or increased, as appropriate, to reflect exchanges and redemptions.  Any endorsement of a Global Note to reflect the amount of any increase or decrease in the aggregate principal amount of outstanding Notes represented thereby will be made by the Trustee or the Custodian, at the direction of the Trustee, in accordance with instructions given by the Holder thereof as required by Section 2.06 hereof.

(c)                                   Euroclear and Clearstream Procedures Applicable.   The provisions of the “Operating Procedures of the Euroclear System” and “Terms and Conditions Governing Use of Euroclear” and the “General Terms and Conditions of Clearstream Banking” and “Customer Handbook” of Clearstream will be applicable to transfers of beneficial interests in the Regulation S Global Note that are held by Participants through Euroclear or Clearstream.

Section 2.02                              Execution and Authentication .

At least one Officer must sign the Notes for the Company by manual or facsimile signature.

If an Officer whose signature is on a Note no longer holds that office at the time a Note is authenticated, the Note will nevertheless be valid.

A Note will not be valid until authenticated by the manual signature of the Trustee.  The signature will be conclusive evidence that the Note has been authenticated under this Indenture.

The Trustee will, upon receipt of a written order of the Company signed by two Officers (an “Authentication Order” ), authenticate Notes for original issue that may be validly issued under this Indenture, including any Additional Notes.  The aggregate principal amount of Notes outstanding at any time may not exceed the aggregate principal amount of Notes authorized for issuance by the Company pursuant to one or more Authentication Orders, except as provided in Section 2.07 hereof.

The Trustee may appoint an authenticating agent acceptable to the Company to authenticate Notes.  An authenticating agent may authenticate Notes whenever the Trustee may do so.  Each reference in this Indenture to authentication by the Trustee includes authentication by such agent.  An authenticating agent has the same rights as an Agent to deal with Holders or an Affiliate of the Company.

Section 2.03                              Registrar and Paying Agent .

The Company will maintain an office or agency where Notes may be presented for registration of transfer or for exchange ( “Registrar” ) and an office or agency where Notes may be presented for payment ( “Paying Agent” ).  The Registrar will keep a register of the Notes and of their transfer and exchange.  The Company may appoint one or more co-registrars and one or more additional paying agents.  The term “Registrar” includes any co-registrar and the term “Paying Agent” includes any additional paying agent.  The Company may change any Paying Agent or Registrar without notice to any Holder.  The Company will notify the Trustee in writing of the name and address of any Agent not a party to this Indenture.  If the Company fails to appoint or maintain another entity as Registrar or Paying Agent, the Trustee shall act as such.  The Company or any of its Subsidiaries may act as Paying Agent or Registrar.

The Company initially appoints The Depository Trust Company ( “DTC” ) to act as Depositary with respect to the Global Notes.

The Company initially appoints the Trustee to act as the Registrar and Paying Agent and to act as Custodian with respect to the Global Notes.

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Section 2.04                              Paying Agent to Hold Money in Trust .

The Company will require each Paying Agent other than the Trustee to agree in writing that the Paying Agent will hold in trust for the benefit of Holders or the Trustee all money held by the Paying Agent for the payment of principal of, premium on, if any, or interest or Special Interest, if any, on, the Notes, and will notify the Trustee, in writing, of any default by the Company in making any such payment.  While any such default continues, the Trustee may require a Paying Agent to pay all money held by it to the Trustee.  The Company at any time may require a Paying Agent to pay all money held by it to the Trustee.  Upon payment over to the Trustee, the Paying Agent (if other than the Company or a Subsidiary) will have no further liability for the money.  If the Company or a Subsidiary acts as Paying Agent, it will segregate and hold in a separate trust fund for the benefit of the Holders all money held by it as Paying Agent.  Upon any bankruptcy or reorganization proceedings relating to the Company, the Trustee will serve as Paying Agent for the Notes.

Section 2.05                              Holder Lists .

The Trustee will preserve in as current a form as is reasonably practicable the most recent list available to it of the names and addresses of all Holders and shall otherwise comply with TIA §312(a).  If the Trustee is not the Registrar, the Company will furnish to the Trustee at least seven Business Days before each interest payment date and at such other times as the Trustee may request in writing, a list in such form and as of such date as the Trustee may reasonably require of the names and addresses of the Holders of Notes and the Company shall otherwise comply with TIA §312(a).

Section 2.06                              Transfer and Exchange .

(a)                                  Transfer and Exchange of Global Notes .  A Global Note may not be transferred except as a whole by the Depositary to a nominee of the Depositary, by a nominee of the Depositary to the Depositary or to another nominee of the Depositary, or by the Depositary or any such nominee to a successor Depositary or a nominee of such successor Depositary.  All Global Notes will be exchanged by the Company for Definitive Notes if:

(i)                                      the Company delivers to the Trustee notice from the Depositary that it is unwilling or unable to continue to act as Depositary or that it is no longer a clearing agency registered under the Exchange Act and, in either case, a successor Depositary is not appointed by the Company within 120 days after the date of such notice from the Depositary;

(ii)                                   the Company in its sole discretion determines that the Global Notes (in whole but not in part) should be exchanged for Definitive Notes and delivers a written notice to such effect to the Trustee; or

(iii)                                there has occurred and is continuing a Default or Event of Default with respect to the Notes.

Upon the occurrence of any of the preceding events in (i), (ii) or (iii) above, Definitive Notes shall be issued in such names as the Depositary shall instruct the Trustee.  Global Notes also may be exchanged or replaced, in whole or in part, as provided in Sections 2.07 and 2.10 hereof.  Every Note authenticated and delivered in exchange for, or in lieu of, a Global Note or any portion thereof, pursuant to this Section 2.06 or Sections 2.07 or 2.10 hereof, shall be authenticated and delivered in the form of, and shall be, a Global Note.  A Global Note may not be exchanged for another Note other than as provided in this Section 2.06(a), however, beneficial interests in a Global Note may be transferred and exchanged as provided in Section 2.06(b), (c) or (f) hereof.

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(b)                                  Transfer and Exchange of Beneficial Interests in the Global Notes .  The transfer and exchange of beneficial interests in the Global Notes will be effected through the Depositary, in accordance with the provisions of this Indenture and the Applicable Procedures.  Beneficial interests in the Restricted Global Notes will be subject to restrictions on transfer comparable to those set forth herein to the extent required by the Securities Act.  Transfers of beneficial interests in the Global Notes also will require compliance with either subparagraph (i) or (ii) below, as applicable, as well as one or more of the other following subparagraphs, as applicable:

(i)                                      Transfer of Beneficial Interests in the Same Global Note .  Beneficial interests in any Restricted Global Note may be transferred to Persons who take delivery thereof in the form of a beneficial interest in the same Restricted Global Note in accordance with the transfer restrictions set forth in the Private Placement Legend; provided, however , that prior to the expiration of the Restricted Period, transfers of beneficial interests in the Regulation S Global Note may not be made to a U.S. Person or for the account or benefit of a U.S. Person (other than an Initial Purchaser).  Beneficial interests in any Unrestricted Global Note may be transferred to Persons who take delivery thereof in the form of a beneficial interest in an Unrestricted Global Note.  No written orders or instructions shall be required to be delivered to the Registrar to effect the transfers described in this Section 2.06(b)(i).

(ii)                                   All Other Transfers and Exchanges of Beneficial Interests in Global Notes.   In connection with all transfers and exchanges of beneficial interests that are not subject to Section 2.06(b)(i) above, the transferor of such beneficial interest must deliver to the Registrar either:

(A)                                both:

(1)                                  a written order from a Participant or an Indirect Participant given to the Depositary in accordance with the Applicable Procedures directing the Depositary to credit or cause to be credited a beneficial interest in another Global Note in an amount equal to the beneficial interest to be transferred or exchanged; and

(2)                                  instructions given in accordance with the Applicable Procedures containing information regarding the Participant account to be credited with such increase; or

(B)                                both:

(1)                                  a written order from a Participant or an Indirect Participant given to the Depositary in accordance with the Applicable Procedures directing the Depositary to cause to be issued a Definitive Note in an amount equal to the beneficial interest to be transferred or exchanged; and

(2)                                  instructions given by the Depositary to the Registrar containing information regarding the Person in whose name such Definitive Note shall be registered to effect the transfer or exchange referred to in (1) above.

Upon consummation of an Exchange Offer by the Company in accordance with Section 2.06(f) hereof, the requirements of this Section 2.06(b)(ii) shall be deemed to have been satisfied upon receipt by the Registrar of the instructions contained in the Letter of Transmittal delivered by the Holder of such beneficial interests in the Restricted Global Notes.  Upon satisfaction of all of the requirements for transfer or exchange of beneficial interests in Global Notes contained in this Indenture and the Notes or

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otherwise applicable under the Securities Act, the Trustee shall adjust the principal amount of the relevant Global Note(s) pursuant to Section 2.06(h) hereof.

(iii)                                Transfer of Beneficial Interests to Another Restricted Global Note.   A beneficial interest in any Restricted Global Note may be transferred to a Person who takes delivery thereof in the form of a beneficial interest in another Restricted Global Note if the transfer complies with the requirements of Section 2.06(b)(ii) above and the Registrar receives the following:

(A)                                if the transferee will take delivery in the form of a beneficial interest in the 144A Global Note, then the transferor must deliver a certificate in the form of Exhibit B hereto, including the certifications in item (1) thereof;

(B)                                if the transferee will take delivery in the form of a beneficial interest in the Regulation S Global Note, then the transferor must deliver a certificate in the form of Exhibit B hereto, including the certifications in item (2) thereof; and

(C)                                if the transferee will take delivery in the form of a beneficial interest in the IAI Global Note, then the transferor must deliver a certificate in the form of Exhibit B hereto, including the certifications, certificates and Opinion of Counsel required by item (3)(d) thereof, if applicable.

(iv)                               Transfer and Exchange of Beneficial Interests in a Restricted Global Note for Beneficial Interests in an Unrestricted Global Note.   A beneficial interest in any Restricted Global Note may be exchanged by any holder thereof for a beneficial interest in an Unrestricted Global Note or transferred to a Person who takes delivery thereof in the form of a beneficial interest in an Unrestricted Global Note if the exchange or transfer complies with the requirements of Section 2.06(b)(ii) above and:

(A)                                such exchange or transfer is effected pursuant to an Exchange Offer in accordance with the applicable Registration Rights Agreement and the holder of the beneficial interest to be transferred, in the case of an exchange, or the transferee, in the case of a transfer, certifies in the applicable Letter of Transmittal that it is not (i) a Broker-Dealer, (ii) a Person participating in the distribution of the Exchange Notes or (iii) a Person who is an affiliate (as defined in Rule 144) of the Company;

(B)                                such transfer is effected pursuant to a Shelf Registration Statement in accordance with the applicable Registration Rights Agreement;

(C)                                such transfer is effected by a Broker-Dealer pursuant to an Exchange Offer Registration Statement in accordance with the applicable Registration Rights Agreement; or

(D)                                the Registrar receives the following:

(1)                                  if the holder of such beneficial interest in a Restricted Global Note proposes to exchange such beneficial interest for a beneficial interest in an Unrestricted Global Note, a certificate from such holder in the form of Exhibit C hereto, including the certifications in item (1)(a) thereof; or

(2)                                  if the holder of such beneficial interest in a Restricted Global Note proposes to transfer such beneficial interest to a Person who shall take

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delivery thereof in the form of a beneficial interest in an Unrestricted Global Note, a certificate from such holder in the form of Exhibit B hereto, including the certifications in item (4) thereof;

and, in each such case set forth in this subparagraph (D), if the Registrar so requests or if the Applicable Procedures so require, an Opinion of Counsel in form reasonably acceptable to the Registrar to the effect that such exchange or transfer is in compliance with the Securities Act and that the restrictions on transfer contained herein and in the Private Placement Legend are no longer required in order to maintain compliance with the Securities Act.

If any such transfer is effected pursuant to subparagraph (B) or (D) above at a time when an Unrestricted Global Note has not yet been issued, the Company shall issue and, upon receipt of an Authentication Order in accordance with Section 2.02 hereof, the Trustee shall authenticate one or more Unrestricted Global Notes in an aggregate principal amount equal to the aggregate principal amount of beneficial interests transferred pursuant to subparagraph (B) or (D) above.

Beneficial interests in an Unrestricted Global Note cannot be exchanged for, or transferred to Persons who take delivery thereof in the form of, a beneficial interest in a Restricted Global Note.

(c)                                   Transfer or Exchange of Beneficial Interests for Definitive Notes .

(i)                                      Beneficial Interests in Restricted Global Notes to Restricted Definitive Notes.   If any holder of a beneficial interest in a Restricted Global Note proposes to exchange such beneficial interest for a Restricted Definitive Note or to transfer such beneficial interest to a Person who takes delivery thereof in the form of a Restricted Definitive Note, then, upon receipt by the Registrar of the following documentation:

(A)                                if the holder of such beneficial interest in a Restricted Global Note proposes to exchange such beneficial interest for a Restricted Definitive Note, a certificate from such holder in the form of Exhibit C hereto, including the certifications in item (2)(a) thereof;

(B)                                if such beneficial interest is being transferred to a QIB in accordance with Rule 144A, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (1) thereof;

(C)                                if such beneficial interest is being transferred to a Non-U.S. Person in an offshore transaction in accordance with Rule 903 or Rule 904, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (2) thereof;

(D)                                if such beneficial interest is being transferred pursuant to an exemption from the registration requirements of the Securities Act in accordance with Rule 144, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (3)(a) thereof;

(E)                                 if such beneficial interest is being transferred to an Institutional Accredited Investor in reliance on an exemption from the registration requirements of the Securities Act other than those listed in subparagraphs (B) through (D) above, a certificate to the effect set forth in Exhibit B hereto, including the certifications, certificates and Opinion of Counsel required by item (3)(d) thereof, if applicable;

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(F)                                  if such beneficial interest is being transferred to the Company or any of its Subsidiaries, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (3)(b) thereof; or

(G)                                if such beneficial interest is being transferred pursuant to an effective registration statement under the Securities Act, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (3)(c) thereof,

the Trustee shall cause the aggregate principal amount of the applicable Global Note to be reduced accordingly pursuant to Section 2.06(h) hereof, and the Company shall execute and the Trustee shall, upon receipt of an Authentication Order, authenticate and deliver to the Person designated in the instructions a Definitive Note in the appropriate principal amount.  Any Definitive Note issued in exchange for a beneficial interest in a Restricted Global Note pursuant to this Section 2.06(c) shall be registered in such name or names and in such authorized denomination or denominations as the holder of such beneficial interest shall instruct the Registrar through instructions from the Depositary and the Participant or Indirect Participant.  The Trustee shall deliver such Definitive Notes to the Persons in whose names such Notes are so registered.  Any Definitive Note issued in exchange for a beneficial interest in a Restricted Global Note pursuant to this Section 2.06(c)(i) shall bear the Private Placement Legend and shall be subject to all restrictions on transfer contained therein.

(ii)                                   Beneficial Interests in Restricted Global Notes to Unrestricted Definitive Notes.   A holder of a beneficial interest in a Restricted Global Note may exchange such beneficial interest for an Unrestricted Definitive Note or may transfer such beneficial interest to a Person who takes delivery thereof in the form of an Unrestricted Definitive Note only if:

(A)                                such exchange or transfer is effected pursuant to an Exchange Offer in accordance with the applicable Registration Rights Agreement and the holder of such beneficial interest, in the case of an exchange, or the transferee, in the case of a transfer, certifies in the applicable Letter of Transmittal that it is not (i) a Broker-Dealer, (ii) a Person participating in the distribution of the Exchange Notes or (iii) a Person who is an affiliate (as defined in Rule 144) of the Company;

(B)                                such transfer is effected pursuant to a Shelf Registration Statement in accordance with the applicable Registration Rights Agreement;

(C)                                such transfer is effected by a Broker-Dealer pursuant to an Exchange Offer Registration Statement in accordance with the applicable Registration Rights Agreement; or

(D)                                the Registrar receives the following:

(1)                                  if the holder of such beneficial interest in a Restricted Global Note proposes to exchange such beneficial interest for an Unrestricted Definitive Note, a certificate from such holder in the form of Exhibit C hereto, including the certifications in item (1)(b) thereof; or

(2)                                  if the holder of such beneficial interest in a Restricted Global Note proposes to transfer such beneficial interest to a Person who shall take delivery thereof in the form of an Unrestricted Definitive Note, a certificate from such holder in the form of Exhibit B hereto, including the certifications in item (4) thereof;

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and, in each such case set forth in this subparagraph (D), if the Registrar so requests or if the Applicable Procedures so require, an Opinion of Counsel in form reasonably acceptable to the Registrar to the effect that such exchange or transfer is in compliance with the Securities Act and that the restrictions on transfer contained herein and in the Private Placement Legend are no longer required in order to maintain compliance with the Securities Act.

(iii)                                Beneficial Interests in Unrestricted Global Notes to Unrestricted Definitive Notes.   If any holder of a beneficial interest in an Unrestricted Global Note proposes to exchange such beneficial interest for a Definitive Note or to transfer such beneficial interest to a Person who takes delivery thereof in the form of a Definitive Note, then, upon satisfaction of the conditions set forth in Section 2.06(b)(ii) hereof, the Trustee will cause the aggregate principal amount of the applicable Unrestricted Global Note to be reduced accordingly pursuant to Section 2.06(h) hereof, and the Company will execute and the Trustee will, upon receipt of an Authentication Order, authenticate and deliver to the Person designated in the instructions a Definitive Note in the appropriate principal amount.  Any Definitive Note issued in exchange for a beneficial interest pursuant to this Section 2.06(c)(iii) will be registered in such name or names and in such authorized denomination or denominations as the holder of such beneficial interest requests through instructions to the Registrar from or through the Depositary and the Participant or Indirect Participant.  The Trustee will deliver such Definitive Notes to the Persons in whose names such Notes are so registered.  Any Definitive Note issued in exchange for a beneficial interest pursuant to this Section 2.06(c)(iii) will not bear the Private Placement Legend.

(d)                                  Transfer and Exchange of Definitive Notes for Beneficial Interests .

(i)                                      Restricted Definitive Notes to Beneficial Interests in Restricted Global Notes.   If any Holder of a Restricted Definitive Note proposes to exchange such Note for a beneficial interest in a Restricted Global Note or to transfer such Restricted Definitive Notes to a Person who takes delivery thereof in the form of a beneficial interest in a Restricted Global Note, then, upon receipt by the Registrar of the following documentation:

(A)                                if the Holder of such Restricted Definitive Note proposes to exchange such Note for a beneficial interest in a Restricted Global Note, a certificate from such Holder in the form of Exhibit C hereto, including the certifications in item (2)(b) thereof;

(B)                                if such Restricted Definitive Note is being transferred to a QIB in accordance with Rule 144A, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (1) thereof;

(C)                                if such Restricted Definitive Note is being transferred to a Non-U.S. Person in an offshore transaction in accordance with Rule 903 or Rule 904, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (2) thereof;

(D)                                if such Restricted Definitive Note is being transferred pursuant to an exemption from the registration requirements of the Securities Act in accordance with Rule 144, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (3)(a) thereof;

(E)                                 if such Restricted Definitive Note is being transferred to an Institutional Accredited Investor in reliance on an exemption from the registration requirements of the Securities Act other than those listed in subparagraphs (B) through (D) above, a

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certificate to the effect set forth in Exhibit B hereto, including the certifications, certificates and Opinion of Counsel required by item (3)(d) thereof, if applicable;

(F)                                  if such Restricted Definitive Note is being transferred to the Company or any of its Subsidiaries, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (3)(b) thereof; or

(G)                                if such Restricted Definitive Note is being transferred pursuant to an effective registration statement under the Securities Act, a certificate to the effect set forth in Exhibit B hereto, including the certifications in item (3)(c) thereof,

the Trustee will cancel the Restricted Definitive Note, increase or cause to be increased the aggregate principal amount of, in the case of clause (A) above, the appropriate Restricted Global Note, in the case of clause (B) above, the 144A Global Note, in the case of clause (C) above, the Regulation S Global Note, and in all other cases, the IAI Global Note.

(ii)                                   Restricted Definitive Notes to Beneficial Interests in Unrestricted Global Notes.   A Holder of a Restricted Definitive Note may exchange such Note for a beneficial interest in an Unrestricted Global Note or transfer such Restricted Definitive Note to a Person who takes delivery thereof in the form of a beneficial interest in an Unrestricted Global Note only if:

(A)                                such exchange or transfer is effected pursuant to an Exchange Offer in accordance with the applicable Registration Rights Agreement and the Holder, in the case of an exchange, or the transferee, in the case of a transfer, certifies in the applicable Letter of Transmittal that it is not (i) a Broker-Dealer, (ii) a Person participating in the distribution of the Exchange Notes or (iii) a Person who is an affiliate (as defined in Rule 144) of the Company;

(B)                                such transfer is effected pursuant to a Shelf Registration Statement in accordance with the applicable Registration Rights Agreement;

(C)                                such transfer is effected by a Broker-Dealer pursuant to an Exchange Offer Registration Statement in accordance with the applicable Registration Rights Agreement; or

(D)                                the Registrar receives the following:

(1)                                  if the Holder of such Definitive Notes proposes to exchange such Notes for a beneficial interest in the Unrestricted Global Note, a certificate from such Holder in the form of Exhibit C hereto, including the certifications in item (1)(c) thereof; or

(2)                                  if the Holder of such Definitive Notes proposes to transfer such Notes to a Person who shall take delivery thereof in the form of a beneficial interest in the Unrestricted Global Note, a certificate from such Holder in the form of Exhibit B hereto, including the certifications in item (4) thereof;

and, in each such case set forth in this subparagraph (D), if the Registrar so requests or if the Applicable Procedures so require, an Opinion of Counsel in form reasonably acceptable to the Registrar to the effect that such exchange or transfer is in compliance

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with the Securities Act and that the restrictions on transfer contained herein and in the Private Placement Legend are no longer required in order to maintain compliance with the Securities Act.

Upon satisfaction of the conditions of any of the subparagraphs in this Section 2.06(d)(ii), the Trustee will cancel the Definitive Notes and increase or cause to be increased the aggregate principal amount of the Unrestricted Global Note.

(iii)                                Unrestricted Definitive Notes to Beneficial Interests in Unrestricted Global Notes.   A Holder of an Unrestricted Definitive Note may exchange such Note for a beneficial interest in an Unrestricted Global Note or transfer such Definitive Notes to a Person who takes delivery thereof in the form of a beneficial interest in an Unrestricted Global Note at any time.  Upon receipt of a request for such an exchange or transfer, the Trustee will cancel the applicable Unrestricted Definitive Note and increase or cause to be increased the aggregate principal amount of one of the Unrestricted Global Notes.

If any such exchange or transfer from a Definitive Note to a beneficial interest is effected pursuant to subparagraphs (ii)(B), (ii)(D) or (iii) above at a time when an Unrestricted Global Note has not yet been issued, the Company will issue and, upon receipt of an Authentication Order in accordance with Section 2.02 hereof, the Trustee will authenticate one or more Unrestricted Global Notes in an aggregate principal amount equal to the principal amount of Definitive Notes so transferred.

(e)                                   Transfer and Exchange of Definitive Notes for Definitive Notes.   Upon request by a Holder of Definitive Notes and such Holder’s compliance with the provisions of this Section 2.06(e), the Registrar will register the transfer or exchange of Definitive Notes.  Prior to such registration of transfer or exchange, the requesting Holder must present or surrender to the Registrar the Definitive Notes duly endorsed or accompanied by a written instruction of transfer in form satisfactory to the Registrar duly executed by such Holder or by its attorney, duly authorized in writing.  In addition, the requesting Holder must provide any additional certifications, documents and information, as applicable, required pursuant to the following provisions of this Section 2.06(e).

(i)                                      Restricted Definitive Notes to Restricted Definitive Notes.   Any Restricted Definitive Note may be transferred to and registered in the name of Persons who take delivery thereof in the form of a Restricted Definitive Note if the Registrar receives the following:

(1)                                  if the transfer will be made pursuant to Rule 144A, then the transferor must deliver a certificate in the form of Exhibit B hereto, including the certifications in item (1) thereof;

(2)                                  if the transfer will be made pursuant to Rule 903 or Rule 904, then the transferor must deliver a certificate in the form of Exhibit B hereto, including the certifications in item (2) thereof; and

(3)                                  if the transfer will be made pursuant to any other exemption from the registration requirements of the Securities Act, then the transferor must deliver a certificate in the form of Exhibit B hereto, including the certifications, certificates and Opinion of Counsel required by item (3)(d) thereof, if applicable.

(ii)                                   Restricted Definitive Notes to Unrestricted Definitive Notes.   Any Restricted Definitive Note may be exchanged by the Holder thereof for an Unrestricted Definitive Note or

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transferred to a Person or Persons who take delivery thereof in the form of an Unrestricted Definitive Note if:

(A)                                such exchange or transfer is effected pursuant to an Exchange Offer in accordance with the applicable Registration Rights Agreement and the Holder, in the case of an exchange, or the transferee, in the case of a transfer, certifies in the applicable Letter of Transmittal that it is not (i) a Broker-Dealer, (ii) a Person participating in the distribution of the Exchange Notes or (iii) a Person who is an affiliate (as defined in Rule 144) of the Company;

(B)                                any such transfer is effected pursuant to a Shelf Registration Statement in accordance with the applicable Registration Rights Agreement;

(C)                                any such transfer is effected by a Broker-Dealer pursuant to an Exchange Offer Registration Statement in accordance with the applicable Registration Rights Agreement; or

(D)                                the Registrar receives the following:

(1)                                  if the Holder of such Restricted Definitive Notes proposes to exchange such Notes for an Unrestricted Definitive Note, a certificate from such Holder in the form of Exhibit C hereto, including the certifications in item (1)(d) thereof; or

(2)                                  if the Holder of such Restricted Definitive Notes proposes to transfer such Notes to a Person who shall take delivery thereof in the form of an Unrestricted Definitive Note, a certificate from such Holder in the form of Exhibit B hereto, including the certifications in item (4) thereof;

and, in each such case set forth in this subparagraph (D), if the Registrar so requests, an Opinion of Counsel in form reasonably acceptable to the Registrar to the effect that such exchange or transfer is in compliance with the Securities Act and that the restrictions on transfer contained herein and in the Private Placement Legend are no longer required in order to maintain compliance with the Securities Act.

(iii)                                Unrestricted Definitive Notes to Unrestricted Definitive Notes.   A Holder of Unrestricted Definitive Notes may transfer such Notes to a Person who takes delivery thereof in the form of an Unrestricted Definitive Note.  Upon receipt of a request to register such a transfer, the Registrar shall register the Unrestricted Definitive Notes pursuant to the instructions from the Holder thereof.

(f)                                    Exchange Offer.   Upon the occurrence of an Exchange Offer in accordance with the applicable Registration Rights Agreement, the Company will issue and, upon receipt of an Authentication Order in accordance with Section 2.02 hereof, the Trustee will authenticate:

(i)                                      one or more Unrestricted Global Notes in an aggregate principal amount equal to the principal amount of the beneficial interests in the Restricted Global Notes accepted for exchange in the Exchange Offer by Persons that certify in the applicable Letters of Transmittal that (A) they are not Broker-Dealers, (B) they are not participating in a distribution of the Exchange Notes and (C) they are not affiliates (as defined in Rule 144) of the Company; and

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(ii)                                   Unrestricted Definitive Notes in an aggregate principal amount equal to the principal amount of the Restricted Definitive Notes accepted for exchange in the Exchange Offer by Persons that certify in the applicable Letters of Transmittal that (A) they are not Broker-Dealers, (B) they are not participating in a distribution of the Exchange Notes and (C) they are not affiliates (as defined in Rule 144) of the Company.

Concurrently with the issuance of such Notes, the Trustee will cause the aggregate principal amount of the applicable Restricted Global Notes to be reduced accordingly, and the Company will execute and the Trustee will, upon receipt of an Authentication Order, authenticate and deliver to the Persons designated by the Holders of Definitive Notes so accepted Unrestricted Definitive Notes in the appropriate principal amount.

(g)                                   Legends .   The following legends will appear on the face of all Global Notes and Definitive Notes issued under this Indenture unless specifically stated otherwise in the applicable provisions of this Indenture.

(i)                                      Private Placement Legend .

(A)                                Except as permitted by subparagraph (B) below, each Global Note and each Definitive Note (and all Notes issued in exchange therefor or substitution thereof) shall bear the legend in substantially the following form:

THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR ANY STATE SECURITIES LAWS. NEITHER  THIS NOTE NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE OFFERED, SOLD, ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF SUCH REGISTRATION OR UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT. THE HOLDER OF ANY NOTE EVIDENCED HEREBY BY ITS ACCEPTANCE HEREOF (1) REPRESENTS THAT (A) IT IS A “QUALIFIED INSTITUTIONAL BUYER” (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT) OR (B) IT IS NOT A U.S. PERSON AND IS ACQUIRING THIS NOTE IN AN “OFFSHORE TRANSACTION” PURSUANT TO RULE 904 OF REGULATION S UNDER THE SECURITIES ACT, (2) AGREES THAT IT WILL NOT, WITHIN THE TIME PERIOD REFERRED TO UNDER RULE 144 (TAKING INTO ACCOUNT THE PROVISIONS OF RULE 144(d) UNDER THE SECURITIES ACT, IF APPLICABLE) UNDER THE SECURITIES ACT AS IN EFFECT ON THE DATE OF THE TRANSFER OF THIS NOTE, OFFER, SELL OR OTHERWISE TRANSFER THIS NOTE EXCEPT (A) TO THE ISSUER OR ANY SUBSIDIARY THEREOF, (B) PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT, (C) FOR SO LONG AS THE NOTES ARE ELIGIBLE FOR RESALE PURSUANT TO RULE 144A UNDER THE SECURITIES ACT (“RULE 144A”), TO A PERSON IT REASONABLY BELIEVES IS A “QUALIFIED INSTITUTIONAL BUYER” AS DEFINED IN RULE 144A THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A, (D) PURSUANT TO OFFERS AND SALES TO NON-U.S. PERSONS THAT OCCUR OUTSIDE THE UNITED STATES WITHIN THE MEANING OF REGULATION S UNDER THE SECURITIES ACT, (E) PURSUANT TO RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE) OR (F) PURSUANT TO ANOTHER AVAILABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND, IN EACH CASE, IN ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS, AND (3) AGREES THAT IT WILL DELIVER TO EACH PERSON TO WHOM THIS NOTE OR AN INTEREST HEREIN IS TRANSFERRED A NOTICE SUBSTANTIALLY TO THE EFFECT OF THIS

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LEGEND. IN CONNECTION WITH ANY TRANSFER OF THIS NOTE OR ANY INTEREST HEREIN WITHIN THE TIME PERIOD REFERRED TO ABOVE, THE HOLDER MUST COMPLETE AND SUBMIT TO THE TRUSTEE THE CERTIFICATE SPECIFIED IN THE INDENTURE RELATING TO THE MANNER OF SUCH TRANSFER (THE FORM OF WHICH CERTIFICATE CAN BE OBTAINED FROM THE TRUSTEE). AS USED HEREIN, THE TERMS “OFFSHORE TRANSACTION,” “UNITED STATES” AND “U.S. PERSON” HAVE THE MEANINGS GIVEN TO THEM BY RULE 902 OF REGULATION S UNDER THE SECURITIES ACT.”

(B)                                Notwithstanding the foregoing, any Global Note or Definitive Note issued pursuant to subparagraphs (b)(iv), (c)(ii), (c)(iii), (d)(ii), (d)(iii), (e)(ii), (e)(iii) or (f) of this Section 2.06 (and all Notes issued in exchange therefor or substitution thereof) will not bear the Private Placement Legend.

(ii)                                   Global Note Legend .  Each Global Note will bear a legend in substantially the following form:

“THIS GLOBAL NOTE IS HELD BY THE DEPOSITARY (AS DEFINED IN THE INDENTURE GOVERNING THIS NOTE) OR ITS NOMINEE IN CUSTODY FOR THE BENEFIT OF THE BENEFICIAL OWNERS HEREOF, AND IS NOT TRANSFERABLE TO ANY PERSON UNDER ANY CIRCUMSTANCES EXCEPT THAT (1) THE TRUSTEE MAY MAKE SUCH NOTATIONS HEREON AS MAY BE REQUIRED PURSUANT TO SECTION 2.06 OF THE INDENTURE, (2) THIS GLOBAL NOTE MAY BE EXCHANGED IN WHOLE BUT NOT IN PART PURSUANT TO SECTION 2.06(a) OF THE INDENTURE, (3) THIS GLOBAL NOTE MAY BE DELIVERED TO THE TRUSTEE FOR CANCELLATION PURSUANT TO SECTION 2.11 OF THE INDENTURE AND (4) THIS GLOBAL NOTE MAY BE TRANSFERRED TO A SUCCESSOR DEPOSITARY WITH THE PRIOR WRITTEN CONSENT OF ION GEOPHYSICAL CORPORATION.

UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN DEFINITIVE FORM, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY.  UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) (“DTC”), TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR SUCH OTHER ENTITY AS MAY BE REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.”

(h)                                  Cancellation and/or Adjustment of Global Notes.   At such time as all beneficial interests in a particular Global Note have been exchanged for beneficial interests in another Global Note or Definitive Notes or a particular Global Note has been redeemed, repurchased or canceled in whole and not in part, each such Global Note will be returned to or retained and canceled by the Trustee in accordance with Section 2.11 hereof.  At any time prior to such cancellation, if any beneficial interest in a Global Note is exchanged for or transferred to a Person who will take delivery thereof in the form of a beneficial interest in another Global Note or for Definitive Notes, the principal amount of Notes represented by such Global Note will be reduced accordingly and an endorsement will be made on such

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Global Note by the Trustee or by the Depositary at the direction of the Trustee to reflect such reduction; and if the beneficial interest is being exchanged for or transferred to a Person who will take delivery thereof in the form of a beneficial interest in another Global Note, such other Global Note will be increased accordingly and an endorsement will be made on such Global Note by the Trustee or by the Depositary at the direction of the Trustee to reflect such increase.

(i)                                      General Provisions Relating to Transfers and Exchanges .

(i)                                      To permit registrations of transfers and exchanges, the Company will execute and the Trustee will authenticate Global Notes and Definitive Notes upon receipt of an Authentication Order in accordance with Section 2.02 hereof or at the Registrar’s request.

(ii)                                   No service charge will be made to a Holder of a beneficial interest in a Global Note or to a Holder of a Definitive Note for any registration of transfer or exchange, but the Company may require payment of a sum sufficient to cover any transfer tax or similar governmental charge payable in connection therewith (other than any such transfer taxes or similar governmental charge payable upon exchange or transfer pursuant to Sections 2.10, 3.06, 3.09, 4.10, 4.14 and 9.05 hereof).

(iii)                                The Registrar will not be required to register the transfer of or exchange of any Note selected for redemption in whole or in part, except the unredeemed portion of any Note being redeemed in part.

(iv)                               All Global Notes and Definitive Notes issued upon any registration of transfer or exchange of Global Notes or Definitive Notes will be the valid obligations of the Company, evidencing the same debt, and entitled to the same benefits under this Indenture, as the Global Notes or Definitive Notes surrendered upon such registration of transfer or exchange.

(v)                                  Neither the Trustee, the Registrar nor the Company will be required:

(A)                                to issue, to register the transfer of or to exchange any Notes during a period beginning at the opening of business 15 days before the day of any selection of Notes for redemption under Section 3.02 hereof and ending at the close of business on the day of selection;

(B)                                to register the transfer of or to exchange any Note selected for redemption in whole or in part, except the unredeemed portion of any Note being redeemed in part; or

(C)                                to register the transfer of or to exchange a Note between a record date and the next succeeding interest payment date.

(vi)                               Prior to due presentment for the registration of a transfer of any Note, the Trustee, any Agent and the Company may deem and treat the Person in whose name any Note is registered as the absolute owner of such Note for the purpose of receiving payment of principal of and interest on such Notes and for all other purposes, and none of the Trustee, any Agent or the Company shall be affected by notice to the contrary.

(vii)                            The Trustee will authenticate Global Notes and Definitive Notes in accordance with the provisions of Section 2.02 hereof.

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(viii)                         All certifications, certificates and Opinions of Counsel required to be submitted to the Registrar pursuant to this Section 2.06 to effect a registration of transfer or exchange may be submitted by facsimile.

(ix)                               Neither the Trustee nor any agent of the Trustee shall have any responsibility for any actions taken or not taken by the Depository.

(x)                                  The Trustee shall have no responsibility or obligation to any Participant or Indirect Participant or any other Person with respect to the accuracy of the books or records, or the acts or omissions, of the Depository or its nominee or of any participant or member thereof, with respect to any ownership interest in the Notes or with respect to the delivery to any Participant or Indirect Participant or other Person (other than the Depository) of any notice (including any notice of redemption) or the payment of any amount, under or with respect to such Notes. All notices and communications to be given to the Holders and all payments to be made to Holders under the Notes shall be given or made only to or upon the order of the registered Holders (which shall be the Depository or its nominee in the case of a Global Note). The rights of beneficial owners in any Global Note shall be exercised only through the Depositary subject to the customary procedures of the Depository. The Trustee may rely and shall be fully protected in relying upon information furnished by the Depository with respect to its Participants or Indirect Participants.

(xi)                               The Trustee shall have no obligation or duty to monitor, determine or inquire as to compliance with any restrictions on transfer imposed under this Indenture or under applicable law with respect to any transfer of any interest in any Note (including any transfers between or among Participants or Indirect Participants in any Global Note) other than to require delivery of such certificates and other documentation or evidence as are expressly required by, and to do so if and when expressly required by, the terms of this Indenture, and to examine the same to determine substantial compliance as to form with the express requirements hereof.

Section 2.07                              Replacement Notes .

If any mutilated Note is surrendered to the Trustee or the Company and the Trustee receives evidence to its satisfaction of the destruction, loss or theft of any Note, the Company will issue and the Trustee, upon receipt of an Authentication Order, will authenticate a replacement Note if the Trustee’s requirements are met.  If required by the Trustee or the Company, an indemnity bond must be supplied by the Holder that is sufficient in the judgment of the Trustee and the Company to protect the Company, the Trustee, any Agent and any authenticating agent from any loss that any of them may suffer if a Note is replaced.  The Company may charge for its expenses in replacing a Note.

Every replacement Note is an additional obligation of the Company and will be entitled to all of the benefits of this Indenture equally and proportionately with all other Notes duly issued hereunder.

Section 2.08                             Outstanding Notes .

The Notes outstanding at any time are all the Notes authenticated by the Trustee except for those canceled by it, those delivered to it for cancellation, those reductions in the interest in a Global Note effected by the Trustee in accordance with the provisions hereof, and those described in this Section 2.08 as not outstanding.  Except as set forth in Section 2.09 hereof, a Note does not cease to be outstanding because the Company or an Affiliate of the Company holds the Note; however, Notes held by the Company or a Subsidiary of the Company shall not be deemed to be outstanding for purposes of Section 3.07(a) hereof.

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If a Note is replaced pursuant to Section 2.07 hereof, it ceases to be outstanding unless the Trustee receives proof satisfactory to it that the replaced Note is held by a protected purchaser.

If the principal amount of any Note is considered paid under Section 4.01 hereof, it ceases to be outstanding and interest on it ceases to accrue.

If the Paying Agent (other than the Company, a Subsidiary or an Affiliate of any thereof) holds, on a redemption date or maturity date, money sufficient to pay Notes payable on that date, then on and after that date such Notes will be deemed to be no longer outstanding and will cease to accrue interest.

Section 2.09                              Treasury Notes .

In determining whether the Holders of the required principal amount of Notes have concurred in any direction, waiver or consent, Notes owned by the Company or any Guarantor, or by any Person directly or indirectly controlling or controlled by or under direct or indirect common control with the Company or any Guarantor, will be considered as though not outstanding, except that for the purposes of determining whether the Trustee will be protected in relying on any such direction, waiver or consent, only Notes that the Trustee knows are so owned will be so disregarded.  Upon request of the Trustee, the Company shall furnish to the Trustee promptly an Officers’ Certificate listing and identifying all Notes, if any, known by the Company to be owned or held by or for the account of any of the above described Persons, and the Trustee shall be entitled to accept and rely upon such Officers’ Certificate as conclusive evidence of the facts therein set forth and of the fact that all Notes not listed therein are outstanding for the purpose of any determination.

Section 2.10                              Temporary Notes .

Until certificates representing Notes are ready for delivery, the Company may prepare and the Trustee, upon receipt of an Authentication Order, will authenticate temporary Notes.  Temporary Notes will be substantially in the form of certificated Notes but may have variations that the Company considers appropriate for temporary Notes and as may be reasonably acceptable to the Trustee.  Without unreasonable delay, the Company will prepare and the Trustee will, upon receipt of an Authentication Order, authenticate definitive Notes in exchange for temporary Notes.

Holders of temporary Notes will be entitled to all of the benefits of this Indenture.

Section 2.11                              Cancellation .

The Company at any time may deliver Notes to the Trustee for cancellation.  The Registrar and Paying Agent will forward to the Trustee any Notes surrendered to them for registration of transfer, exchange or payment.  The Trustee and no one else will cancel all Notes surrendered for registration of transfer, exchange, payment, replacement or cancellation and will destroy canceled Notes (subject to the record retention requirements of the Exchange Act).  Certification of the destruction of all canceled Notes will be delivered to the Company.  The Company may not issue new Notes to replace Notes that it has paid or that have been delivered to the Trustee for cancellation.

Section 2.12                              Defaulted Interest .

If the Company defaults in a payment of interest on the Notes, it will pay the defaulted interest in any lawful manner plus, to the extent lawful, interest payable on the defaulted interest, to the Persons who are Holders on a subsequent special record date, in each case at the rate provided in the Notes and in Section 4.01 hereof.  The Company will notify the Trustee in writing of the amount of defaulted interest

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proposed to be paid on each Note and the date of the proposed payment.  The Company will fix or cause to be fixed each such special record date and payment date; provided that no such special record date may be less than 10 days prior to the related payment date for such defaulted interest.  At least 15 days before the special record date, the Company (or, upon the written request of the Company, the Trustee in the name and at the expense of the Company) will mail or cause to be mailed to Holders a notice that states the special record date, the related payment date and the amount of such interest to be paid.

ARTICLE 3
REDEMPTION AND PREPAYMENT

Section 3.01                              Notices to Trustee .

If the Company elects to redeem Notes pursuant to the optional redemption provisions of Section 3.07 hereof, it must furnish to the Trustee, at least 30 days but not more than 60 days before a redemption date, an Officers’ Certificate setting forth:

(i)                                      the clause of this Indenture pursuant to which the redemption shall occur;

(ii)                                   the redemption date;

(iii)                                the principal amount of Notes to be redeemed; and

(iv)                               the redemption price.

Section 3.02                              Selection of Notes to Be Redeemed or Purchased .

If less than all of the Notes are to be redeemed or purchased in an offer to purchase at any time, the Trustee will select Notes for redemption or purchase on a pro rata basis or, in the case of Notes issued in global form pursuant to Article 2 hereof, based on a method as DTC may require unless otherwise required by law or applicable stock exchange or depositary requirements.

The Trustee will promptly notify the Company in writing of the Notes selected for redemption or purchase and, in the case of any Note selected for partial redemption or purchase, the principal amount thereof to be redeemed or purchased.  Notes and portions of Notes selected will be in amounts of $2,000 or whole multiples of $1,000 in excess thereof; except that if all of the Notes of a Holder are to be redeemed or purchased, the entire outstanding amount of Notes held by such Holder shall be redeemed or purchased.  Except as provided in the preceding sentence, provisions of this Indenture that apply to Notes called for redemption or purchase also apply to portions of Notes called for redemption or purchase.

Section 3.03                              Notice of Redemption .

Subject to the provisions of Section 3.09 hereof, at least 30 days but not more than 60 days before a redemption date, the Company will mail or cause to be mailed, by first class mail, a notice of redemption to each Holder whose Notes are to be redeemed at its registered address, except that redemption notices may be mailed more than 60 days prior to a redemption date if the notice is issued in connection with a defeasance of the Notes or a satisfaction and discharge of this Indenture pursuant to Articles 8 or 12 hereof.  Notice of any redemption, including, without limitation, upon an Equity Offering, may, at the Company’s discretion, be subject to one or more conditions precedent, including, but not limited to, completion of the related Equity Offering.

The notice will identify the Notes to be redeemed and will state:

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(i)                                      the redemption date;

(ii)                                   the redemption price;

(iii)                                if any Note is being redeemed in part, the portion of the principal amount of such Note to be redeemed and that, after the redemption date upon surrender of such Note, a new Note or Notes in principal amount equal to the unredeemed portion will be issued upon cancellation of the original Note;

(iv)                               the name and address of the Paying Agent;

(v)                                  that Notes called for redemption must be surrendered to the Paying Agent to collect the redemption price;

(vi)                               that, unless the Company defaults in making such redemption payment, interest on Notes called for redemption ceases to accrue on and after the redemption date;

(vii)                            the paragraph of the Notes and/or Section of this Indenture pursuant to which the Notes called for redemption are being redeemed; and

(viii)                         that no representation is made as to the correctness or accuracy of the CUSIP number, if any, listed in such notice or printed on the Notes.

At the Company’s request, the Trustee will give the notice of redemption in the Company’s name and at its expense; provided, however , that the Company has delivered to the Trustee, at least 45 days prior to the redemption date, an Officers’ Certificate requesting that the Trustee give such notice and setting forth the information to be stated in such notice as provided in the preceding paragraph.

Section 3.04                              Effect of Notice of Redemption .

Once notice of redemption is mailed in accordance with Section 3.03 hereof, Notes called for redemption become due and payable on the redemption date at the redemption price, unless the redemption is subject to a condition precedent that is not satisfied or waived.

Section 3.05                              Deposit of Redemption or Purchase Price .

At least one Business Day prior to the redemption or purchase date, the Company will deposit with the Trustee or with the Paying Agent money sufficient to pay the redemption or purchase price of, accrued interest and Special Interest, if any, on all Notes to be redeemed or purchased on that date.  The Trustee or the Paying Agent will promptly return to the Company any money deposited with the Trustee or the Paying Agent by the Company in excess of the amounts necessary to pay the redemption or purchase price of, accrued interest and Special Interest, if any, on all Notes to be redeemed or purchased.

If the Company complies with the provisions of the preceding paragraph, on and after the redemption or purchase date, interest will cease to accrue on the Notes or the portions of Notes called for redemption or accepted for purchase.  If a Note is redeemed or purchased on or after an interest record date but on or prior to the related interest payment date, then any accrued and unpaid interest shall be paid to the Person in whose name such Note was registered at the close of business on such record date.  If any Note called for redemption or purchase is not so paid upon surrender for redemption or tendered for purchase because of the failure of the Company to comply with the preceding paragraph, interest shall be paid on the unpaid principal, from the redemption or purchase date until such principal is paid, and to the

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extent lawful on any interest not paid on such unpaid principal, in each case at the rate provided in the Notes and in Section 4.01 hereof.

Section 3.06                              Notes Redeemed or Purchased in Part .

Upon surrender of a Note that is redeemed or purchased in part, the Company will issue and, upon receipt of an Authentication Order, the Trustee will authenticate for the Holder at the expense of the Company a new Note equal in principal amount to the unredeemed or unpurchased portion of the Note surrendered.

Section 3.07                              Optional Redemption .

(a)                                  At any time prior to May 15, 2015, the Company may on any one or more occasions redeem up to 35% of the aggregate principal amount of Notes issued under this Indenture, upon not less than 30 nor more than 60 days’ notice, at a redemption price equal to 108.125% of the principal amount of the Notes redeemed, plus accrued and unpaid interest and Special Interest, if any, to the date of redemption (subject to the rights of Holders of Notes on the relevant record date to receive interest on the relevant interest payment date), in an amount not to exceed the net proceeds from an Equity Offering by the Company; provided that:

(i)                                      at least 65% of the aggregate principal amount of Notes originally issued under this Indenture (excluding Notes held by the Company and its Subsidiaries) remains outstanding immediately after the occurrence of such redemption; and

(ii)                                   the redemption occurs within 90 days of the date of the closing of such Equity Offering.

(b)                                  At any time prior to May 15, 2015, the Company may on any one or more occasions redeem all or a part of the Notes, upon not less than 30 nor more than 60 days’ notice, at a redemption price equal to 100% of the principal amount of the Notes redeemed, plus the Applicable Premium as of, and accrued and unpaid interest and Special Interest, if any, to the applicable date of redemption, subject to the rights of Holders on the relevant record date to receive interest due on the relevant interest payment date.

(c)                                   Except pursuant to the preceding paragraphs and Section 4.14(e), the Notes will not be redeemable at the Company’s option prior to May 15, 2015.

(d)                                  On or after May 15, 2015, the Company may on any one or more occasions redeem all or a part of the Notes, upon not less than 30 nor more than 60 days’ notice, at the redemption prices (expressed as percentages of principal amount) set forth below, plus accrued and unpaid interest and Special Interest, if any, on the Notes redeemed, to the applicable date of redemption, if redeemed during the twelve-month period beginning on May 15 of the years indicated below, subject to the rights of Holders on the relevant record date to receive interest on the relevant interest payment date:

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Unless the Company defaults in the payment of the redemption price, interest will cease to accrue on the Notes or portions thereof called for redemption on the applicable redemption date.

(e)                                   Any redemption pursuant to this Section 3.07 shall be made pursuant to the provisions of Sections 3.01 through 3.06 hereof.

Section 3.08                              Mandatory Redemption .

Except as set forth below under Sections 4.10 and 4.14 hereof, the Company is not required to make mandatory redemption or sinking fund payments with respect to the Notes or to repurchase the Notes at the option of Holders of the Notes.

Section 3.09                              Offer to Purchase by Application of Excess Proceeds .

In the event that, pursuant to Section 4.10 hereof, the Company is required to commence an offer to all Holders to purchase Notes (an “Asset Sale Offer” ), it will follow the procedures specified below.

The Asset Sale Offer shall be made to all Holders and all holders of Parity Lien Debt containing provisions similar to those set forth in this Indenture with respect to offers to purchase, prepay or redeem with the proceeds of sales of assets.  The Asset Sale Offer shall remain open for a period of at least 20 Business Days following its commencement and not more than 30 Business Days, except to the extent that a longer period is required by applicable law (the “Offer Period” ).  No later than three Business Days after the termination of the Offer Period (the “Purchase Date” ), the Company will apply all Excess Proceeds (the “Offer Amount”) to the purchase of Notes and such other Parity Lien Debt (on a pro rata basis based on the principal amount of Notes and such other Parity Lien Debt surrendered, if applicable) or, if less than the Offer Amount has been tendered, all Notes and other Parity Lien Debt tendered in response to the Asset Sale Offer.  Payment for any Notes so purchased will be made in the same manner as interest payments are made.

If the Purchase Date is on or after an interest record date and on or before the related interest payment date, any accrued and unpaid interest and Special Interest, if any, will be paid to the Person in whose name a Note is registered at the close of business on such record date, and no additional interest will be payable to Holders who tender Notes pursuant to the Asset Sale Offer.

Upon the commencement of an Asset Sale Offer, the Company will send, by first class mail, a notice to the Trustee and each of the Holders, with a copy to the Trustee.  The notice will contain all instructions and materials necessary to enable such Holders to tender Notes pursuant to the Asset Sale Offer.  The notice, which will govern the terms of the Asset Sale Offer, will state:

(i)                                      that the Asset Sale Offer is being made pursuant to this Section 3.09 and Section 4.10 hereof and the length of time the Asset Sale Offer will remain open;

(ii)                                   the Offer Amount, the purchase price and the Purchase Date;

(iii)                                that any Note not tendered or accepted for payment will continue to  accrue interest;

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(iv)                               that, unless the Company defaults in making such payment, any Note accepted for payment pursuant to the Asset Sale Offer will cease to accrue interest after the Purchase Date;

(v)                                  that Holders electing to have a Note purchased pursuant to an Asset Sale Offer may elect to have Notes purchased in denominations of $2,000 or an integral multiple of $1,000 in excess thereof;

(vi)                               that Holders electing to have Notes purchased pursuant to any Asset Sale Offer will be required to surrender the Note, with the form entitled “Option of Holder to Elect Purchase” attached to the Notes completed, or transfer by book-entry transfer, to the Company, a Depositary, if appointed by the Company, or a Paying Agent at the address specified in the notice at least three days before the Purchase Date;

(vii)                            that Holders will be entitled to withdraw their election if the Company, the Depositary or the Paying Agent, as the case may be, receives, not later than the expiration of the Offer Period, a telegram, telex, facsimile transmission or letter setting forth the name of the Holder, the principal amount of the Note the Holder delivered for purchase and a statement that such Holder is withdrawing his election to have such Note purchased;

(viii)                         that, if the aggregate principal amount of Notes and other Parity Lien Debt surrendered by holders thereof exceeds the Offer Amount, the Company will select the Notes and other Parity Lien Debt to be purchased on a pro rata basis based on the principal amount of Notes and such other Parity Lien Debt surrendered (with such adjustments as may be deemed appropriate by the Company so that only Notes in denominations of $2,000, or an integral multiple of $1,000 in excess thereof, will be purchased); and

(ix)                               that Holders whose Notes were purchased only in part will be issued new Notes equal in principal amount to the unpurchased portion of the Notes surrendered (or transferred by book-entry transfer).

On or before the Purchase Date, the Company will, to the extent lawful, accept for payment, on a pro rata basis to the extent necessary, the Offer Amount of Notes or portions thereof tendered pursuant to the Asset Sale Offer, or if less than the Offer Amount has been tendered, all Notes tendered, and will deliver or cause to be delivered to the Trustee the Notes properly accepted together with an Officers’ Certificate stating that such Notes or portions thereof were accepted for payment by the Company in accordance with the terms of this Section 3.09.  The Company, the Depositary or the Paying Agent, as the case may be, will promptly (but in any case not later than five days after the Purchase Date) mail or deliver to each tendering Holder an amount equal to the purchase price of the Notes tendered by such Holder and accepted by the Company for purchase, and the Company will promptly issue a new Note, and the Trustee, upon receipt of an Authentication Order, will authenticate and mail or deliver (or cause to be transferred by book entry) such new Note to such Holder, in a principal amount equal to any unpurchased portion of the Note surrendered.  Any Note not so accepted shall be promptly mailed or delivered by the Company to the Holder thereof.  The Company will publicly announce the results of the Asset Sale Offer on the Purchase Date.

Other than as specifically provided in this Section 3.09, any purchase pursuant to this Section 3.09 shall be made pursuant to the provisions of Sections 3.01 through 3.06 hereof.

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ARTICLE 4
COVENANTS

Section 4.01                              Payment of Notes .

The Company will pay or cause to be paid the principal of, premium on, if any, interest and Special Interest, if any, on, the Notes on the dates and in the manner provided in the Notes.  Principal, premium, if any, interest and Special Interest, if any, will be considered paid on the date due if the Paying Agent, if other than the Company or a Subsidiary thereof, holds as of 10:00 a.m. Eastern Time on the due date money deposited by the Company in immediately available funds and designated for and sufficient to pay all principal, premium, if any, and interest, if any, then due.  The Company will pay all Special Interest, if any, in the same manner on the dates and in the amounts set forth in the applicable Registration Rights Agreement.

The Company will pay interest (including post-petition interest in any proceeding under any Bankruptcy Law) on overdue principal at a rate that is 1% higher than the then applicable interest rate on the Notes to the extent lawful; it will pay interest (including post-petition interest in any proceeding under any Bankruptcy Law) on overdue installments of interest and Special Interest, if any (without regard to any applicable grace period), at the same rate to the extent lawful.

Section 4.02                              Maintenance of Office or Agency .

The Company will maintain an office or agency (which may be an office of the Trustee or an affiliate of the Trustee, Registrar or co-registrar) where Notes may be surrendered for registration of transfer or for exchange and where notices and demands to or upon the Company in respect of the Notes and this Indenture may be served.  The Company will give prompt written notice to the Trustee of the location, and any change in the location, of such office or agency.  If at any time the Company fails to maintain any such required office or agency or fails to furnish the Trustee with the address thereof, such presentations, surrenders, notices and demands may be made or served at the Corporate Trust Office of the Trustee.

The Company may also from time to time designate one or more other offices or agencies where the Notes may be presented or surrendered for any or all such purposes and may from time to time rescind such designations.  The Company will give prompt written notice to the Trustee of any such designation or rescission and of any change in the location of any such other office or agency.

The Company hereby designates the Corporate Trust Office of the Trustee as one such office or agency of the Company in accordance with Section 2.03 hereof.

Section 4.03                              Reports .

(a)                                  Whether or not required by the rules and regulations of the SEC, so long as any Notes are outstanding, the Company will furnish to the Holders of Notes  (or file with the SEC for public availability), within the time periods specified in the SEC’s rules and regulations:

(i)                                      all quarterly and annual reports that would be required to be filed with the SEC on Forms 10-Q and 10-K if the Company were required to file such reports, including a “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and, with respect to the annual information only, a report thereon by the Company’s certified independent accountants; and

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(ii)                                   all current reports that would be required to be filed with the SEC on Form 8-K if the Company were required to file such reports.

All such reports will be prepared in all material respects in accordance with all of the rules and regulations applicable to such reports. In addition, the Company will file a copy of each of the reports referred to in clauses (i) and (ii) above with the SEC for public availability within the time periods specified in the rules and regulations applicable to such reports (unless the SEC will not accept such a filing) and will post the reports on its website within those time periods. The Company will at all times comply with TIA §314(a).

If, at any time, the Company is no longer subject to the periodic reporting requirements of the Exchange Act for any reason, the Company will nevertheless continue filing the reports specified in the preceding paragraphs with the SEC within the time periods specified above unless the SEC will not accept such a filing.  The Company will not take any action for the purpose of causing the SEC not to accept any such filings.  If, notwithstanding the foregoing, the SEC will not accept the Company’s filings for any reason, the Company will post the reports referred to in the preceding paragraphs on its website within the time periods that would apply if the Company were required to file those reports with the SEC.

(b)                                  If the Company has designated any of its Subsidiaries as Unrestricted Subsidiaries, then the quarterly and annual financial information required by paragraph (a) of this Section 4.03 will include a reasonably detailed presentation, either on the face of the financial statements or in the footnotes thereto, and in Management’s Discussion and Analysis of Financial Condition and Results of Operations, of the financial condition and results of operations of the Company and its Restricted Subsidiaries separate from the financial condition and results of operations of the Unrestricted Subsidiaries of the Company.

(c)                                   For so long as any Notes remain outstanding, if at any time they are not required to file with the SEC the reports required by paragraphs (a) and (b) of this Section 4.03, the Company and the Guarantors will furnish to the Holders and to securities analysts and prospective investors, upon their request, the information required to be delivered pursuant to Rule 144A(d)(4) under the Securities Act.

Section 4.04                              Compliance Certificate .

(a)                                  The Company and each Guarantor (to the extent that such Guarantor is so required under the TIA) shall deliver to the Trustee, within 90 days after the end of each fiscal year (beginning with the fiscal year ending on December 31, 2013), an Officers’ Certificate stating that a review of the activities of the Company and its Subsidiaries during the preceding fiscal year has been made under the supervision of the signing Officers with a view to determining whether the Company has kept, observed, performed and fulfilled its obligations under this Indenture and the Security Documents, and further stating, as to each such Officer signing such certificate, that to the best of his or her knowledge the Company has kept, observed, performed and fulfilled each and every covenant contained in this Indenture and the Security Documents and is not in default in the performance or observance of any of the terms, provisions and conditions of this Indenture or the Security Documents (or, if a Default or Event of Default has occurred, describing all such Defaults or Events of Default of which he or she may have knowledge and what action the Company is taking or proposes to take with respect thereto) and that to the best of his or her knowledge no event has occurred and remains in existence by reason of which payments on account of the principal of, premium on, if any, interest or Special Interest, if any, on the Notes is prohibited or if such event has occurred, a description of the event and what action the Company is taking or proposes to take with respect thereto.

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(b)                                  So long as not contrary to the then current recommendations of the American Institute of Certified Public Accountants, the year-end financial statements delivered pursuant to Section 4.03 above shall be accompanied by a written statement of the Company’s independent public accountants (who shall be a firm of established national reputation) that in making the examination necessary for certification of such financial statements, nothing has come to their attention that would lead them to believe that the Company has violated any provisions of Article 4 or Article 5 hereof or, if any such violation has occurred, specifying the nature and period of existence thereof, it being understood that such accountants shall not be liable directly or indirectly to any Person for any failure to obtain knowledge of any such violation.

(c)                                   So long as any of the Notes are outstanding, the Company will deliver to the Trustee, forthwith upon any Officer becoming aware of any Default or Event of Default, an Officers’ Certificate specifying such Default or Event of Default and what action the Company is taking or proposes to take with respect thereto.

Section 4.05                              Taxes .

The Company will pay, and will cause each of its Subsidiaries to pay, prior to delinquency, all material taxes, assessments, and governmental levies except such as are contested in good faith and by appropriate proceedings or where the failure to effect such payment is not adverse in any material respect to the Holders of the Notes.

Section 4.06                              Stay, Extension and Usury Laws .

The Company and each of the Guarantors covenants (to the extent that it may lawfully do so) that it will not at any time insist upon, plead, or in any manner whatsoever claim or take the benefit or advantage of, any stay, extension or usury law wherever enacted, now or at any time hereafter in force, that may affect the covenants or the performance of this Indenture; and the Company and each of the Guarantors (to the extent that it may lawfully do so) hereby expressly waives all benefit or advantage of any such law, and covenants that it will not, by resort to any such law, hinder, delay or impede the execution of any power herein granted to the Trustee, but will suffer and permit the execution of every such power as though no such law has been enacted.

Section 4.07                              Restricted Payments .

(a)                                  The Company will not, and will not permit any of its Restricted Subsidiaries to, directly or indirectly:

(i)                                      declare or pay any dividend or make any other payment or distribution on account of the Company’s or any of its Restricted Subsidiaries’ Equity Interests (including, without limitation, any payment in connection with any merger or consolidation involving the Company or any of its Restricted Subsidiaries) or to the direct or indirect holders of the Company’s or any of its Restricted Subsidiaries’ Equity Interests in their capacity as such (other than dividends or distributions payable in Equity Interests (other than Disqualified Stock) of the Company and other than dividends or distributions payable to the Company or a Restricted Subsidiary of the Company);

(ii)                                   purchase, redeem or otherwise acquire or retire for value (including, without limitation, in connection with any merger or consolidation involving the Company) any Equity Interests of the Company or any direct or indirect parent of the Company;

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(iii)                                make any payment on or with respect to, or purchase, redeem, defease or otherwise acquire or retire for value any Indebtedness of the Company or any Guarantor that is contractually subordinated to the Notes or to any Note Guarantee (excluding (A) any intercompany Indebtedness between or among the Company and any of its Restricted Subsidiaries, (B) the purchase, redemption, defeasance, repurchase or other acquisition or retirement for value of Indebtedness that is subordinated in right of payment to the Notes or the Note Guarantees purchased, redeemed, defeased or otherwise acquired or retired for value in anticipation of satisfying a sinking fund obligation, principal installment or final maturity, in each case due within one year of the date of purchase, repurchase, redemption, defeasance or other acquisition or retirement for value, and (C) a payment of interest or principal at the Stated Maturity thereof); or

(iv)                               make any Restricted Investment (all such payments and other actions set forth in these clauses (i) through (iv) above being collectively referred to as “Restricted Payments” ),

unless, at the time of and after giving effect to such Restricted Payment:

(A)                                no Default or Event of Default has occurred and is continuing or would occur as a consequence of such Restricted Payment;

(B)                                the Company would, at the time of such Restricted Payment and after giving pro forma effect thereto as if such Restricted Payment had been made at the beginning of the applicable four-quarter period, have been permitted to incur at least $1.00 of additional Indebtedness pursuant to the Fixed Charge Coverage Ratio test set forth in Section 4.09(a) hereof; and

(C)                                such Restricted Payment, together with the aggregate amount of all other Restricted Payments made by the Company and its Restricted Subsidiaries since the date of this Indenture (excluding Restricted Payments permitted by clauses (ii) through (xiv) of paragraph (b) of this Section 4.07), is less than the sum, without duplication, of:

(1)                                  50% of the Consolidated Net Income of the Company for the period (taken as one accounting period and without duplication of amounts used in the calculation of clause (15) of the definition of Permitted Investments) from April 1, 2013 to the last day of the Company’s last fiscal quarter ending prior to the Restricted Payment for which internal financial statements are in existence at the time of such Restricted Payment (or, if such Consolidated Net Income for such period is a deficit, less 100% of such deficit); plus

(2)                                  100% of the aggregate net cash proceeds and the Fair Market Value of any Capital Stock of Persons engaged in a Permitted Business or any other assets that are used or useful in a Permitted Business in each case received by the Company after the date of this Indenture as a contribution to its common equity capital or from the issue or sale of Equity Interests of the Company (other than Disqualified Stock); plus

(3)                                  (a) to the extent that any Restricted Investment that was made after the date of this Indenture is sold for cash (other than to the Company or any of its Restricted Subsidiaries) or otherwise canceled, liquidated or repaid for cash, the cash return of capital to the Company or any of its Restricted Subsidiaries with respect to such Restricted Investment resulting from such sale,

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liquidation or repayment (less the out-of-pocket cost of any such disposition, if any) and (b) the net reduction in Restricted Investments resulting from repayments of loans or advances or other transfers of assets in each case to the Company or any Restricted Subsidiary from any Person (including without limitation, Unrestricted Subsidiaries) and any dividends received in cash by the Company or a Restricted Subsidiary of the Company from an Unrestricted Subsidiary of the Company (to the extent that such dividends were not otherwise included in the Consolidated Net Income of the Company for such period); plus

(4)                                  the amount by which Indebtedness of the Company or its Restricted Subsidiaries is reduced on the Company’s balance sheet upon the conversion or exchange (other than by a Subsidiary of the Company) subsequent to the date of this Indenture of any such Indebtedness of the Company or its Restricted Subsidiaries into or for Equity Interests (other than Disqualified Stock) of the Company (less the amount of any cash, or the Fair Market Value of any other property (other than such Equity Interests), distributed by the Company upon such conversion or exchange and excluding the net cash proceeds from the conversion or exchange financed, directly or indirectly, using funds borrowed from the Company or any Subsidiary), together with the net proceeds, if any, received by the Company or any of its Restricted Subsidiaries upon such conversion or exchange; plus

(5)                                  to the extent that any Unrestricted Subsidiary of the Company designated as such after the date of this Indenture is redesignated as a Restricted Subsidiary pursuant to the terms of this Indenture or is merged or consolidated with or into, or transfers or otherwise disposes of all or substantially all of its properties or assets to or is liquidated into, the Company or a Restricted Subsidiary after the date of this Indenture, the Fair Market Value of the Company’s Restricted Investment in such Subsidiary (or of the properties or assets disposed of, as applicable) as of the date of such redesignation, merger, consolidation, transfer, disposition or liquidation.

(b)                                  The provisions of Section 4.07(a) hereof will not prohibit:

(i)                                      the payment of any dividend or the consummation of any irrevocable redemption within 60 days after the date of declaration of the dividend or giving of the redemption notice, as the case may be, if at the date of declaration or notice, the dividend or redemption payment would have complied with the provisions of this Indenture;

(ii)                                   the making of any Restricted Payment in exchange for, or out of or with the net cash proceeds of the substantially concurrent sale (other than to a Restricted Subsidiary of the Company) of, Equity Interests of the Company (other than Disqualified Stock) or from the substantially concurrent contribution of common equity capital to the Company; provided that the amount of any such net cash proceeds that are utilized for any such Restricted Payment will be excluded from Section 4.07(a)(iii)(B) and will not be considered to be net cash proceeds from an Equity Offering for purposes of Section 3.07 hereof;

(iii)                                the payment of any dividend (or, in the case of any partnership or limited liability company, any similar distribution) by a Restricted Subsidiary of the Company to the holders of its Equity Interests on a pro rata basis or on a basis more favorable to the Company or a Restricted Subsidiary;

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(iv)                               the repurchase, redemption, defeasance or other acquisition or retirement for value of Indebtedness of the Company or any Guarantor that is contractually subordinated to the Notes or to any Note Guarantee with the net cash proceeds from a substantially concurrent incurrence of Permitted Refinancing Indebtedness;

(v)                                  so long as no Default (other than a Reporting Default) or Event of Default has occurred and is continuing, the repurchase, redemption or other acquisition or retirement for value of any Equity Interests of the Company or any Restricted Subsidiary of the Company held by any current or former officer, director or employee of the Company or any of its Restricted Subsidiaries pursuant to any equity subscription agreement, stock option agreement, shareholders’ agreement or similar agreement; provided that the aggregate price paid for all such repurchased, redeemed, acquired or retired Equity Interests may not exceed $5.0 million in any twelve-month period; provided, further , that the Company may carry over and make in subsequent twelve-month periods, in addition to the amounts permitted for such twelve-month period, up to $5.0 million of unutilized capacity under this clause (v) attributable to the immediately preceding twelve-month period; provided, further , that such amount in any twelve-month period may be increased by an amount not to exceed:

(A)                                the cash proceeds from the sale of Equity Interests of the Company and, to the extent contributed to the Company as common equity capital, the cash proceeds from the sale of Equity Interests of any of the Company’s direct or indirect parent companies, in each case to members of management, directors or consultants of the Company, any of its Subsidiaries or any of its direct or indirect parent companies that occurs after the date of this Indenture to the extent the cash proceeds from the sale of Equity Interests have not otherwise been applied to the making of Restricted Payments pursuant to Sections 4.07(a)(iii)(B) or Section 4.07(b)(ii) or to an optional redemption of Notes pursuant to Section 3.07 hereof; plus

(B)                                the cash proceeds of key man life insurance policies received by the Company or its Restricted Subsidiaries after the date of this Indenture; and

in addition, cancellation of Indebtedness owing to the Company from any current or former officer, director or employee (or any permitted transferees thereof) of the Company or any of its Restricted Subsidiaries (or any direct or indirect parent company thereof), in connection with a repurchase of Equity Interests of the Company from such Persons will not be deemed to constitute a Restricted Payment for purposes of this Section 4.07 or any other provisions of this Indenture;

(vi)                               the repurchase of Equity Interests deemed to occur upon the exercise of stock or other equity options to the extent such Equity Interests represent a portion of the exercise price of those stock or other equity options and any repurchase or other acquisition of Equity Interests made in lieu of withholding taxes in connection with any exercise or exchange of stock options, warrants, incentives or other rights to acquire Equity Interests;

(vii)                            so long as no Default or Event of Default has occurred and is continuing, the declaration and payment of regularly scheduled or accrued dividends to holders of any class or series of Disqualified Stock of the Company, or any preferred stock of any Restricted Subsidiary of the Company issued on or after the date of this Indenture in accordance with the Fixed Charge Coverage Ratio test described in Section 4.09(a) hereof;

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(viii)                         payments of cash, dividends, distributions, advances or other Restricted Payments by the Company or any of its Restricted Subsidiaries to allow the payment of cash in lieu of the issuance of fractional shares upon (i) the exercise of options or warrants or (ii) the conversion or exchange of Capital Stock of any such Person;

(ix)                               repurchases of Indebtedness that is subordinated in right of payment to the Notes or a Note Guarantee at a purchase price not greater than (i) 101% of the principal amount of such subordinated Indebtedness in the event of a Change of Control or (ii) 100% of the principal amount of such subordinated Indebtedness in the event of an Asset Sale, in each case plus accrued and unpaid interest thereon, in connection with any change of control offer or asset sale offer required by the terms of such Indebtedness, but only if:

(A)                                in the case of a Change of Control, the Company has first complied with and fully satisfied its obligations under Section 4.14 hereof; or

(B)                                in the case of an Asset Sale, the Company has complied with and fully satisfied its obligations in accordance with Sections 3.09 and 4.10 hereof;

(x)                                  so long as no Default (other than a Reporting Default) or Event of Default has occurred and is continuing, the payment to the holder(s) of shares of Series D Preferred Stock outstanding on the date of this Indenture in a total amount of up to $10.0 million in connection with the conversion or repurchase of the shares of Series D Preferred Stock outstanding on such date and the payment of dividends thereon;

(xi)                               any distributions or payments to dissenting stockholders in connection with a consolidation, merger or transfer of assets in connection with a transaction that is not prohibited by this Indenture, in an amount not to exceed $5.0 million;

(xii)                            the distribution, as a dividend or otherwise, of shares of Capital Stock of, or Indebtedness owed to the Company or a Restricted Subsidiary by, Unrestricted Subsidiaries (other than Unrestricted Subsidiaries, the primary assets of which are cash and Cash Equivalents);