Amendment of Original Side Letter. MPAC, Sponsor and Crestview agree that Section 1 of the Original Side Letter is hereby amended as follows:

The Original Side Letter provides for the transfer and assignment of the Sponsor Transferred Shares by Sponsor to Crestview following the satisfaction of a Vesting Condition. A Vesting Condition has not yet occurred; however, in connection with winding up its operations, Sponsor desires to transfer and assign the Sponsor Transferred Shares to Crestview on the date of this letter (this “First Amendment to Side Letter”) rather than following the satisfaction of a Vesting Condition. MPAC, Sponsor and Crestview are entering into this First Amendment to Side Letter in order to # amend the Original Side Letter to provide for such transfer and assignment to occur on the date hereof and # effect such transfer and assignment and related matters in accordance with the Original Side Letter, as amended by this First Amendment to Side Letter (as amended, the “Side Letter”).

Side Agreements. By signing below, Participant hereby confirms that, since Participant’s first day of employment with the Company, Participant has not entered into and Participant is not aware of the existence of any oral or written side agreements with any third party including resellers, distributors or customers that modify or supersede the terms of either the Company’s invoice, written contracts or purchase orders with these resellers, distributors or customers. In addition, Participant agrees not to engage in such activity in the future and to immediately notify the Company if he/she becomes aware of such activity. Additionally, completion of the quarterly sales certification is a requirement of the compensation plan.

Amendment to Original Agreement. Section 7.1(b) of the Original Agreement is hereby amended as follows: the text “April 23, 2021” in Section 7.1(b) of the Original Agreement is hereby deleted and the text “May 24, 2021” is inserted therefor.

Reference is made to that certain side letter (the “Original Side Letter”), dated as of November 9, 2018, by and among Matlin & Partners Acquisition Corporation, a Delaware corporation (now known as U.S. Well Services, Inc., “MPAC”), Matlin & Partners Acquisition Sponsor LLC, a Delaware limited liability company (“Sponsor”), Crestview III USWS, L.P., a Delaware limited partnership (“Crestview Investor I”), and Crestview III USWS TE, LLC, a Delaware limited liability company (“Crestview Investor II” and together with Crestview Investor I, “Crestview”). Capitalized terms used but not defined herein shall have the meaning given to such terms in the Original Side Letter.

“Side Letter” means any “side letter” (if any) between an Investor and Borrower.

Private Side Designation. Each Public Lender agrees to cause at least one individual at or on behalf of such Public Lender to at all times have selected the “Private Side Information” or similar designation on the content declaration screen of the Platform in order to enable such Public Lender or its delegate, in accordance with such Public Lender’s compliance procedures and Applicable Law, including United States Federal and state securities Applicable Laws, to make reference to Borrower Materials that are not made available through the “Public Side Information” portion of the Platform and that may contain material non-public information with respect to the Borrower or its securities for purposes of United States Federal or state securities Applicable Laws.

Miscellaneous. This First Amendment to Side Letter shall be governed by, and construed in accordance with, the laws of the State of New York, without regard to the principles of conflicts of laws that would otherwise require the application of the law of any other state, and may be executed in one or more counterparts (including by facsimile or electronic mail or in .pdf) and by different parties hereto in separate counterparts, with the same effect as if all parties had signed the same document. All counterparts so executed and delivered shall be construed together and shall constitute one and the same agreement. Except as hereby amended, the Original Side Letter shall remain in full force and effect.

One Original. With respect to each Receivable with respect to which the related Contract does not constitute an Electronic Contract, there is only one executed original of the Contract (except in the case of a Convenience Check) related to such Receivable. Further, the Contract relating to such Receivable described in the preceding sentence does not have any stamps, marks or notations indicating any interest of any other Person, or if it has any stamps, marks or notations indicating an interest of any other Person, such stamps, marks or notations have been cancelled or voided (or if such stamp, mark or notation is in the name of an agent (or any predecessor agent) under the Senior Revolver, the Borrower has the right to cancel or void such stamp, mark or notation without the consent of such agent (or any predecessor agent, as applicable) and such agent (or any predecessor agent, as applicable) has released in writing its lien on such Contract).

Original Effective Date. The Original Effective Date is the date as of which the Plan was initially adopted.