Joinder to Sponsor Agreement. Transferee hereby agrees to be bound by:

Sponsor Agreement. On or prior to the Closing Date, BRPA, the Sponsor, and BRAC shall enter into an agreement in a form and on terms and conditions reasonably acceptable to the Company (the “Sponsor Agreement”) providing that, immediately prior to the Effective Time:

Joinder – Crestview Investor I JOINDER TO SPONSOR AGREEMENT AND LETTER AGREEMENT This Joinder to Sponsor Agreement and Letter Agreement, dated as of ​ (this “Joinder”), is executed by Crestview III USWS, L.P., a Delaware limited partnership (“Transferee”), in favor of U.S. Well Services, Inc., a Delaware corporation (formerly Matlin & Partners Acquisition Corporation) (the “Company”), pursuant to [Section 3(d)] of the Sponsor Agreement (as defined below) and paragraph 7(c) of the Letter Agreement (as defined below). Each capitalized term used and not otherwise defined in this Joinder has the meaning given to such term in the Sponsor Agreement.

Joinder to Letter Agreement. Transferee hereby agrees to be bound by paragraph 6(b), paragraph 7(a) (subject to paragraph 7(c)) and paragraphs 11 through 16 of the Letter Agreement; in each case, to the same extent as if Transferee were an original party to the Letter Agreement (but solely for the purpose of the provisions of the Letter Agreement specified above and solely with respect to the Transferee Conversion Shares).

Sponsor Investment. The Agents shall have received reasonably satisfactory evidence that the Permitted Holders made a cash equity contribution to Ultimate Parent of at least ​.

Pursuant to each of the Agreements, the New Sponsor hereby: # acknowledges that the New Sponsor has received and reviewed a complete copy of such Agreement; and # acknowledges and agrees that upon execution and delivery of this Joinder to the other parties to such Agreement, the New Sponsor shall become a party to such Agreement, and will be fully bound by, and subject to, all of the terms and conditions of such Agreement, as amended or modified by this Joinder, as a party thereunder as though an original party thereto for all purposes of such Agreement.

The Sponsor hereby assigns 431,250 Shares and 5,375,000 Warrants to the New Sponsor. Within a reasonable time after the date hereof, the Sponsor shall instruct AST, # to record the transfer of the Shares and Warrants to the New Sponsor pursuant to this Joinder and # to confirm to the Sponsor in writing that such transfer has been duly recorded.

“Joinder” means a joinder agreement substantially in the form of [Exhibit J-11]1]] to this Agreement.

“Joinder Agreement” means a joinder agreement in form and substance reasonably satisfactory to the Administrative Agent.

“Commitment Joinder Agreement” means a joinder agreement substantially in the form attached as [Exhibit A] hereto.