SPECIFIC TERMS IN THIS EXHIBIT HAVE BEEN REDACTED BECAUSE SUCH TERMS ARE NOT
MATERIAL AND WOULD BE COMPETITIVELY HARMFUL IF PUBLICLY DISCLOSED. SUCH TERMS
HAVE BEEN MARKED AT THE APPROPRIATE PLACE WITH THREE ASTERISKS (***)

December 12, 2019
Liberty Oilfield Services, LLC
950 17th Street, Suite 2000
Denver, Colorado 80202

Re: Master Product Purchase Agreement and Ancillary Agreements

Dear Sir or Madam:

This letter agreement is in regards to: (i) that certain Master Product Purchase
Agreement, by and between Smart Sand, Inc. (“Smart Sand”) and Liberty Oilfield
Services, LLC (“Liberty”), dated March 8, 2017, as amended by that certain First
Amendment to Master Product Purchase Agreement, dated effective as of May 1,
2017, and those certain letter agreements entered into by the parties from time
to time (as amended, the “PPA”); (ii) that certain Railcar Usage Agreement,
dated March 8, 2017, as amended by that certain First Amendment to Railcar Usage
Agreement, dated effective as of May 1, 2017 (as amended, the “RUA”); and (iii)
that certain Transportation and Transloading Services Agreement, dated August 7,
2018, by and between Smart Sand, SSI Bakken I, LLC, and Liberty (as amended, the
“Transloading Agreement”). All capitalized terms contained in this letter
agreement and not otherwise defined shall have the meanings ascribed to such
terms in the PPA, RUA and Transloading Agreement, as applicable.
Per our discussion, Smart Sand and Liberty each hereby agrees to the following:

1.During the period commencing on the date on which this letter agreement is
executed by all parties and ending on September 30, 2020 (the “Credit Period”),
Liberty shall be eligible for a credit equal to *** for each ton of *** Products
purchased during the Credit Period, *** for each ton of *** Products purchased
during the Credit Period, and *** for each ton of *** Products purchased during
the Credit Period. Notwithstanding the foregoing, if the Average Cushing
Oklahoma WTI Spot Prices per barrel for the preceding calendar quarter is less
than ***, then the credit for *** Products, *** Products and *** Products shall
be ***, *** and ***, respectively. Liberty shall also be eligible for a credit
equal to *** towards the *** transloading charge for each ton of Products
shipped on the Union Pacific Railroad, as described in Section 2.1 of the PPA.
During the Credit Period: (i) the prices payable for Services under the
Transloading Agreement shall be ***, which is inclusive of amounts due for
Products under the PPA; and (ii) the *** railcar usage fee set forth in Section
1.A. of the RUA shall be waived.

2.If Liberty purchases less than *** tons of Products in a calendar month (the
“Minimum Benchmark”) during the period commencing on *** and ending on *** (the
“2019 Adjustment Period”), then Liberty shall pay to Smart Sand an amount (the
“Monthly Shortfall Payment”) equal to the product of *** multiplied by the
difference between the Minimum Benchmark and the tons of Products purchased in
such month (such difference, the “Monthly Shortfall Amount”) (i.e. (i) Monthly
Shortfall Payment = *** Monthly Shortfall Amount; and (ii) Monthly Shortfall
Amount = Minimum Benchmark – Products purchased).

3.During the period commencing on *** and ending on ***, so long as Liberty has
paid all Monthly Shortfall Payments in full, all monthly purchases of Products
in excess of the Minimum Benchmark shall be credited by *** (the “Make-Up
Credit”). By way of example, if the total

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Monthly Shortfall Amount during the 2019 Adjustment Period is *** and Liberty
purchases *** in ***, then the price payable for *** tons in each such month
shall be reduced by *** and Liberty shall not be entitled to any further Make-Up
Credits after February 2020. Any excess tons for which Liberty receives the ***
credit hereunder shall not be deemed Prior Excess under the PPA. For the
avoidance of doubt, Liberty shall not be entitled to any Make-Up Credit after
***.

4.The deferral rights set forth in Section 1.5 of the PPA shall be suspended
during the 2019 Adjustment Period, and the Monthly Shortfall Amount, if any,
shall not be deemed to be Deferred Tons under the PPA. As of ***, Liberty has
*** Deferred Tons outstanding under the PPA and such amount shall remain
unchanged during the 2019 Adjustment Period. Solely for purposes of calculating
the Quarterly Shortfall Payment under the PPA, if any, payable for the quarter
ending January 31, 2020, the month of January 2020 shall be deemed to be the
entire quarter, and the Minimum Tons per Quarter for such quarter shall be
deemed to be ***.

5.The reference to *** in Section 2.3 of the PPA shall be changed to ***.

6.Liberty shall lease from Smart Sand, pursuant to a Master Storage Lease
Agreement to be entered into contemporaneously herewith by Smart Sand and
Liberty (the “Master Storage Agreement”): (i) commencing on ***, *** fleets of
Smart Sand’s SmartDepot™ storage silos (consisting of *** silos per fleet) at a
monthly rent of *** per individual silo (i.e. *** per fleet); and (ii)
commencing on ***, *** additional fleet of Smart Sand’s SmartDepot™ storage
silos (consisting of *** silos per fleet) at a monthly rent of *** per
individual silo (i.e. *** per fleet). The silos shall be delivered to Smart
Sand’s Van Hook, ND rail terminal and the Master Storage Agreement shall
terminate no earlier than ***. In connection with leasing the foregoing
SmartDepot™ storage silos, Liberty has the option to lease *** rapid deployment
trailer at a monthly rent of ***.

7.The obligations of Smart Sand under this letter agreement (including providing
the credits set forth herein) are conditioned upon Liberty’s execution of the
Master Storage Agreement, and Liberty’s performance of all obligations under the
PPA, RUA, Transloading Agreement, and the Master Storage Agreement (including
the equipment schedules thereto).

8.Except as expressly set forth in this letter agreement, all of the terms and
conditions of the PPA, RUA and Transloading Agreement shall remain unchanged and
in full force and effect.

[signature page follows]

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Please indicate your agreement to the terms of this letter agreement by signing
in the space provided below and returning it to me. This letter agreement may be
executed in counterparts and delivered via facsimile or other electronic
transmission, each of which shall be deemed to be an original and both of which
together shall constitute one and the same agreement.

SMART SAND, INC.

By: _/s/ John Young_1-2-20_____________
John Young, Chief Operating Officer

SSI BAKKEN I, LLC

By: _/s/ John Young 1-2-20__________________
John Young, Chief Operating Officer

Confirmed, acknowledged and agreed to this 12th day of December, 2019:

LIBERTY OILFIELD SERVICES, LLC

By: _/s/ Ronald Gusek_______________________
Name: Ronald Gusek
Title President