FOREIGN GUARANTY

Exhibit 10.4

EXECUTION COPY

FOREIGN GUARANTY

Dated as of April 27, 2006

From

THE GUARANTORS NAMED HEREIN

And

THE ADDITIONAL GUARANTORS REFERRED TO HEREIN

as Guarantors

in favor of

THE SECURED PARTIES REFERRED TO IN

THE CREDIT AGREEMENT REFERRED TO HEREIN

Foreign Guaranty

T A B L E O F C O N T E N T S

Exhibit A - Guaranty Supplement

Foreign Guaranty

FOREIGN GUARANTY

FOREIGN GUARANTY dated as of April 27, 2006 made by the Persons listed on the signature pages hereof under the caption “Foreign Guarantors” and the Additional Guarantors (as defined in Section 8(b) ) (such Persons so listed and the Additional Guarantors being, collectively, the “ Guarantors ” and, individually, each a “ Guarantor ”) in favor of the Secured Parties (as defined in the Credit Agreement referred to below).

PRELIMINARY STATEMENT.

SENSATA TECHNOLOGIES B.V., a private limited liability company ( besloten vennootschap met beperkte aansprakelijkheid ) incorporated under the laws of the Netherlands (the “ BV Borrower ”), SENSATA TECHNOLOGIES FINANCE COMPANY, LLC, a Delaware limited liability company (the “ US Borrower ”; together with the BV Borrower, the “ Borrowers ”), SENSATA TECHNOLOGIES INTERMEDIATE HOLDING B.V., a private limited liability company ( besloten vennootschap met beperkte aansprakelijkheid ) incorporated under the laws of the Netherlands, are party to a Credit Agreement dated as of April 27, 2006 (as amended, amended and restated, supplemented or otherwise modified from time to time, the “ Credit Agreement ”; the capitalized terms defined therein and not otherwise defined herein being used herein as therein defined) with certain Lenders party thereto, the Initial L/C Issuer, the Initial Swing Line Lender and MORGAN STANLEY SENIOR FUNDING, INC., as Collateral Agent and Administrative Agent. The Borrowers and the Guarantors have entered into or may from time to time enter into lines of credit (committed or uncommitted) and other similar arrangements (the “ Bilateral Obligations ”) with Lenders or their Affiliates and certain other financial institutions as initially set forth on Schedule XII of the Domestic Security Agreement and as such schedule may be amended from time to time upon written notice by the Borrowers to the applicable Lenders or Affiliates and certain other financial institutions (each, in such capacity, a “ Bilateral Provider ”).

Each Guarantor may receive, directly or indirectly, a portion of the proceeds of the Loans under the Credit Agreement and will derive substantial direct and indirect benefits from the transactions contemplated by the Credit Agreement and from each Bilateral Provider’s Bilateral Obligations. It is a condition precedent to the making of the Loans by the Lenders and the issuance of Letters of Credit by the Initial L/C Issuer under the Credit Agreement and the entry by the Hedge Banks into Secured Hedge Agreements from time to time that each Guarantor shall have executed and delivered this Guaranty.

NOW, THEREFORE, in consideration of the premises and in order to induce the Lenders to make Loans and to issue Letters of Credit under the Credit Agreement, the Bilateral Providers to provide Bilateral Obligations and the Hedge Banks to enter into Secured Hedge Agreements from time to time, each Guarantor, jointly and severally with each other Guarantor, hereby agrees as follows:

Section 1. Guaranty; Limitation of Liability . (a) Each Guarantor hereby absolutely, unconditionally and irrevocably guarantees the punctual payment when due, whether at scheduled maturity or on any date of a required prepayment or by acceleration, demand or otherwise, of all Obligations of the BV Borrower, each Loan Party guaranteeing the Obligations of the BV Borrower and each other Foreign Subsidiary that is an obligor with respect to the Cash Management Obligations now or hereafter existing (including, without limitation, any extensions, modifications, substitutions, amendments or renewals of any or all of the foregoing Obligations), whether direct or indirect, absolute or contingent, and whether for principal, interest, premiums, fees, indemnities, contract causes of action, costs, expenses or otherwise and the Bilateral Obligations of each Bilateral Provider (such Obligations being the “ Guaranteed Obligations ”), and agrees to pay any and all reasonable expenses (including, without limitation, reasonable fees and reasonable out-of-pocket expenses of counsel) incurred by the

Foreign Guaranty

Administrative Agent or any other Secured Party in enforcing any rights under this Guaranty or any other Loan Document in accordance with Section 10.04 of the Credit Agreement (including Attorney Costs of any law firm or other external counsel to the Administrative Agent); provided , however , that in no event shall the Guaranteed Obligations of any Guarantor include any of its obligations as a Borrower under the Credit Agreement. Without limiting the generality of the foregoing, each Guarantor’s liability shall extend to all amounts that constitute part of the Guaranteed Obligations and would be owed by any other Guarantor to any Secured Party under or in respect of the Loan Documents but for the fact that they are unenforceable or not allowable due to the existence of a bankruptcy, reorganization or similar proceeding involving such other Guarantor. Notwithstanding anything herein or in the Credit Agreement to the contrary, (i) the aggregate principal amount of all Bilateral Obligations guaranteed hereby shall not exceed $40,000,000 and (ii) to the extent that Bilateral Obligations are cash collateralized or otherwise guaranteed (other than pursuant hereunder), such Bilateral Obligations shall not be guaranteed hereby.

(b) Each Guarantor (other than the BV Borrower), and by its acceptance of this Guaranty, the Administrative Agent and each other Secured Party, hereby confirm that it is the intention of all such Persons that this Guaranty and the Obligations of each Guarantor hereunder not constitute a fraudulent transfer or conveyance for purposes of Bankruptcy Law (as hereinafter defined), the Uniform Fraudulent Conveyance Act, the Uniform Fraudulent Transfer Act or any similar foreign, federal or state Law to the extent applicable to this Guaranty and the Obligations of each Guarantor hereunder. To effectuate the foregoing intention, the Administrative Agent, the other Secured Parties and the Guarantors hereby irrevocably agree that the Obligations of each Guarantor (other than the BV Borrower in its capacity as a Borrower under the Credit Agreement) under this Guaranty at any time shall be limited to the maximum amount as will result in the Obligations of such Guarantor under this Guaranty not constituting a fraudulent transfer or conveyance. For purposes hereof, “ Bankruptcy Law ” means any proceeding of the type referred to in Section 8.01(f) of the Credit Agreement or Title 11, U.S. Code, or any similar foreign, federal or state Law for the relief of debtors.

(c) Each Guarantor hereby unconditionally and irrevocably agrees that in the event any payment shall be required to be made to any Secured Party under this Guaranty or any other guaranty, such Guarantor will contribute, to the maximum extent permitted by Law, such amounts to each other Guarantor and each other guarantor so as to maximize the aggregate amount paid to the Secured Parties under or in respect of the Loan Documents.

(d) To the extent that any Guarantor shall be required hereunder to pay a portion of the Guaranteed Obligations exceeding the greater of (a) the amount of the economic benefit actually received by such Guarantor from the Loans and (b) the amount such Guarantor would otherwise have paid if such Guarantor had paid the aggregate amount of the Guaranteed Obligations (excluding the amount thereof repaid by the Borrowers) in the same proportion as such Guarantor’s net worth at the date enforcement is sought hereunder bears to the aggregate net worth of all the Guarantors (taken together with the aggregate net worth of all other “ Guarantors ” (as such term is defined in the Credit Agreement) obligated with respect to the Guaranteed Obligations (the “ Other Guarantors ”)) at the date of enforcement is sought hereunder, then each Other Guarantor shall reimburse such other Guarantors for the amount of such excess, pro rata, based on the respective net worths of such Other Guarantors at the date enforcement hereunder is sought.

(e) Notwithstanding anything to the contrary in any Loan Document, no Guarantor shall have any liability or obligation under this Guaranty to the extent that such liability or obligation would constitute unlawful financial assistance under the applicable Laws of the jurisdiction of any Guarantor.

Section 2. Guaranty Absolute . Each Guarantor guarantees that the Guaranteed Obligations will be paid strictly in accordance with the terms of the Loan Documents, regardless of any

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Law, regulation or order now or hereafter in effect in any jurisdiction affecting any of such terms or the rights of any Secured Party with respect thereto. The Obligations of each Guarantor under or in respect of this Guaranty are independent of the Guaranteed Obligations or any other Obligations of any other Loan Party under or in respect of the Loan Documents, and a separate action or actions may be brought and prosecuted against each Guarantor to enforce this Guaranty, irrespective of whether any action is brought against the BV Borrower (in its capacity as Borrower under the Credit Agreement) or any other Loan Party or whether the BV Borrower or any other Loan Party is joined in any such action or actions. The liability of each Guarantor under this Guaranty shall be irrevocable, absolute and unconditional irrespective of, and each Guarantor hereby irrevocably waives any defenses it may now have or hereafter acquire in any way relating to, any or all of the following:

(a) any lack of validity or enforceability of any Loan Document or any agreement or instrument relating thereto;

(b) any change in the time, manner or place of payment of, or in any other term of, all or any of the Guaranteed Obligations or any other Obligations of any other Loan Party under or in respect of the Loan Documents, or any other amendment or waiver of or any consent to departure from any Loan Document, including, without limitation, any increase in the Guaranteed Obligations resulting from the extension of additional credit to any Loan Party or any of its Subsidiaries or otherwise; provided that where such a waiver is unenforceable or where such a change would discharge the Guarantor of its liability under this Guaranty if made without its consent, the Guarantor hereby gives its consent to such change;

(c) any taking, exchange, release or non-perfection of any Collateral or any other collateral, or any taking, release or amendment or waiver of, or consent to departure from, any other guaranty, for all or any of the Guaranteed Obligations;

(d) any manner of application of Collateral or any other collateral, or proceeds thereof, to all or any of the Guaranteed Obligations, or any manner of sale or other disposition of any Collateral or any other collateral for all or any of the Guaranteed Obligations or any other Obligations of any Loan Party under the Loan Documents or any other assets of any Loan Party or any of its Subsidiaries;

(e) any change, restructuring or termination of the corporate structure or existence of any Loan Party or any of its Subsidiaries;

(f) any failure of any Secured Party to disclose to any Loan Party any information relating to the business, condition (financial or otherwise), operations, performance, properties or prospects of any other Loan Party now or hereafter known to such Secured Party (each Guarantor waiving any duty on the part of the Secured Parties to disclose such information);

(g) the failure of any other Person to execute or deliver this Guaranty, any Guaranty Supplement (as hereinafter defined) or any other guaranty or agreement or the release or reduction of liability of any Guarantor or other guarantor or surety with respect to the Guaranteed Obligations; or

(h) any other circumstance (including, without limitation, any statute of limitations) or any existence of or reliance on any representation by any Secured Party that might otherwise constitute a defense available to, or a discharge of, any Loan Party or any other guarantor or surety to the extent permitted; provided that, where a Loan Party contracts with the Secured Parties to be discharged from the Guaranteed Obligations, the Guarantor hereby assents to such contract and remains bound under this Guaranty.

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This Guaranty shall continue to be effective or be reinstated, as the case may be, if at any time any payment of any of the Guaranteed Obligations is rescinded or must otherwise be returned by any Secured Party or any other Person upon the insolvency, bankruptcy or reorganization of the BV Borrower (in its capacity as a Borrower under the Credit Agreement) or any other Loan Party or otherwise, all as though such payment had not been made.

Section 3. Waivers and Acknowledgments . (a) Each Guarantor hereby unconditionally and irrevocably waives promptness, diligence, notice of acceptance, presentment, demand for performance, notice of nonperformance, default, acceleration, protest or dishonor and any other notice with respect to any of the Guaranteed Obligations and this Guaranty and any requirement that any Secured Party protect, secure, perfect or insure any Lien or any property subject thereto or exhaust any right or take any action against any Loan Party or any other Person or any Collateral.

(b) Each Guarantor hereby unconditionally and irrevocably waives any right to revoke this Guaranty and, where it may not waive this right, the Guarantor agrees that this Guaranty will not be revoked, and acknowledges that this Guaranty is continuing in nature and applies to all Guaranteed Obligations, whether existing now or in the future.

(c) Each Guarantor hereby unconditionally and irrevocably waives (i) any defense arising by reason of any claim or defense based upon an election of remedies by any Secured Party that in any manner impairs, reduces, releases or otherwise adversely affects the subrogation, reimbursement, exoneration, contribution or indemnification rights of such Guarantor or other rights of such Guarantor to proceed against any of the other Loan Parties, any other guarantor or any other Person or any Collateral and (ii) any defense based on any right of set-off or counterclaim against or in respect of the Obligations of such Guarantor hereunder.

(d) Each Guarantor acknowledges that the Collateral Agent may, without notice to or demand upon such Guarantor and without affecting the liability of such Guarantor under this Guaranty, foreclose under any mortgage by nonjudicial sale, and each Guarantor hereby waives any defense to the recovery by the Collateral Agent and the other Secured Parties against such Guarantor of any deficiency after such nonjudicial sale and any defense or benefits that may be afforded by applicable Law.

(e) Each Guarantor hereby unconditionally and irrevocably waives any duty on the part of any Secured Party to disclose to such Guarantor any matter, fact or thing relating to the business, condition (financial or otherwise), operations, performance, properties or prospects of any other Loan Party or any of its Subsidiaries now or hereafter known by such Secured Party.

(f) Each Guarantor acknowledges that it will receive substantial direct and indirect benefits from the financing arrangements contemplated by the Loan Documents and that the waivers set forth in Section 2 and this Section 3 are knowingly made in contemplation of such benefits.

(g) To the fullest extent permitted by law, each Guarantor organized under the laws of Mexico unconditionally and irrevocably waives, any right to which it may be entitled, to the extent applicable, under Articles 2813, 2814,2815,2816, 2817, 2818, 2819, 2820, 2821, 2822, 2823, 2824, 2826, 2827, 2830, 2835, 2836, 2837, 2838, 2839, 2840, 2842, 2844, 2846, 2847, 2848 and 2849 of the Federal Civil Code ( Código Civil Federal ) and the corresponding provisions of the Civil Codes of the States of Mexico and the Federal District.

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(h) Each Guarantor organized under the laws of Brazil hereby unconditionally and irrevocably waives the rights and benefits under Articles 364, 365, 827, 829, 834, 835, 837, 838 and 839 of the Brazilian Civil Code.

Section 4. Subrogation . Each Guarantor hereby unconditionally and irrevocably agrees not to exercise any rights that it may now have or hereafter acquire against the BV Borrower, any other Loan Party or any other insider guarantor that arise from the existence, payment, performance or enforcement of such Guarantor’s Obligations under or in respect of this Guaranty or any other Loan Document, including, without limitation, any right of subrogation, reimbursement, exoneration, contribution or indemnification and any right to participate in any claim or remedy of any Secured Party against the BV Borrower, any other Loan Party or any other insider guarantor or any Collateral, whether or not such claim, remedy or right arises in equity or under contract, statute or common Law, including, without limitation, the right to take or receive from the BV Borrower, any other Loan Party or any other insider guarantor, directly or indirectly, in cash or other property or by set-off or in any other manner, payment or security on account of such claim, remedy or right, unless and until all of the Guaranteed Obligations (other than (x) obligations with respect to Secured Hedge Agreements, (y) Cash Management Obligations not yet due and payable and (z) contingent indemnification obligations not yet accrued and payable under the Loan Documents) and all other amounts payable under this Guaranty shall have been paid in full in cash, all Letters of Credit shall have been cash collateralized or otherwise back-stopped, in each case, on terms required by the Credit Agreement or shall have expired or been terminated and the Commitments shall have expired or been terminated. If any amount shall be paid to any Guarantor in violation of the immediately preceding sentence at any time prior to the latest of (a) the payment in full in cash of the Guaranteed Obligations and all other amounts payable under this Guaranty, (b) the Maturity Date of the Term Loan Facility and (c) the latest date of cash collateralization or other back-stop, in each case, on the terms required by the Credit Agreement or the expiration or termination of all Letters of Credit, such amounts shall be received and held in trust for the benefit of the Secured Parties, shall be segregated from other property and funds of such Guarantor and shall forthwith be paid or delivered to the Administrative Agent in the same form as so received (with any necessary endorsement or assignment) to be credited and applied to the Guaranteed Obligations and all other amounts payable under this Guaranty, whether matured or unmatured, in accordance with the terms of the Loan Documents, or to be held as Collateral for any Guaranteed Obligations or other amounts payable under this Guaranty thereafter arising. If (i) any Guarantor shall make payment to any Secured Party of all or any part of the Guaranteed Obligations, (ii) all of the Guaranteed Obligations and all other amounts, if any, payable under this Guaranty shall have been paid in full in cash, (iii) the Maturity Date of the Term Loan Facility shall have occurred and (iv) all Letters of Credit shall have been cash collateralized or otherwise back-stopped, in each case, on the terms required under the Credit Agreement, or shall have expired or been terminated, the Secured Parties will, at such Guarantor’s request and expense, execute and deliver to such Guarantor appropriate documents, without recourse and without representation or warranty, necessary to evidence the transfer by subrogation to such Guarantor of an interest in the Guaranteed Obligations resulting from such payment made by such Guarantor pursuant to this Guaranty.

Section 5. P