NGS · Natural Gas Services Group Inc

Not applicable. Each Restricted Stock Unit represents the right to receive one share of the Issuer's common stock upon vesting.

Not Applicable. The acquisition reflects an award of Restricted Stock Units pursuant to the Company's 2019 Equity Incentive Plan. The award vests on the first anniversary of the grant date, subject to accelerated vesting under certain circumstances.

Not applicable. Each Restricted Stock Unit represents the right to receive one share of the Issuer's common stock upon vesting.

Not Applicable. The acquisition reflects an award of Restricted Stock Units pursuant to the Company's 2019 Equity Incentive Plan. The award vests on the first anniversary of the grant date, subject to accelerated vesting under certain circumstances.

Not applicable. Each Restricted Stock Unit represents the right to receive one share of the Issuer's common stock upon vesting.

Not Applicable. The acquisition reflects an award of Restricted Stock Units pursuant to the Company's 2019 Equity Incentive Plan. The award vests on the first anniversary of the grant date, subject to accelerated vesting under certain circumstances.

Not applicable. Each Restricted Stock Unit represents the right to receive one share of the Issuer's common stock upon vesting.

Not Applicable. The acquisition reflects an award of Restricted Stock Units pursuant to the Company's 2019 Equity Incentive Plan. The award vests on the first anniversary of the grant date, subject to accelerated vesting under certain circumstances.

Not applicable. Each RSU represented the right to receive one share of the Issuer's common stock upon vesting.

Not Applicable. The acquisition reflects an award of Restricted Stock Units pursuant to the Company's 2019 Equity Incentive Plan. The award vests on the first anniversary of the grant date, subject to accelerated vesting under certain circumstances.

Not applicable. Each Restricted Stock Unit represents the right to receive one share of the Issuer's common stock upon vesting.

Not Applicable. The acquisition reflects an award of Restricted Stock Units pursuant to the Company's 2019 Equity Incentive Plan. The award vests on the first anniversary of the grant date, subject to accelerated vesting under certain circumstances.

Shares acquired through reinvestment of cash dividends pursuant to the terms of the deferred compensation plan.

Shares acquired through reinvestment of cash dividends pursuant to the terms of the deferred compensation plan.

Not applicable. The reported shares were acquired in connection with the vesting of a restricted stock unit (RSU) award.

Not applicable. Each RSU represented the right to receive one share of the Issuer's common stock upon vesting (or upon election by the reporting person, up to 50% of the RSUs in cash).

Not applicable. The reported shares were acquired in connection with the vesting of a restricted stock unit (RSU) award.

Represents an election by the reporting person to receive 50% of the value of the RSUs in cash.

Not applicable. The reported shares were acquired in connection with the vesting of a restricted stock unit (RSU) award.

Not applicable. Each RSU represented the right to receive one share of the Issuer's common stock upon vesting (or upon election by the reporting person, up to 50% of the RSUs in cash).

Not applicable. The reported shares were acquired in connection with the vesting of a restricted stock unit (RSU) award.

Not applicable. Each RSU represented the right to receive one share of the Issuer's common stock upon vesting (or upon election by the reporting person, up to 50% of the RSUs in cash).

Represents an election by the reporting person to receive 50% of the value of the RSUs in cash.

Not applicable. The reported shares were acquired in connection with the vesting of a restricted stock unit (RSU) award.

Not applicable. Each RSU represented the right to receive one share of the Issuer's common stock upon vesting (or upon election by the reporting person, up to 50% of the RSUs in cash).

Not applicable. The reported shares were acquired in connection with the vesting of a restricted stock unit (RSU) award.

Not applicable. Each RSU represented the right to receive one share of the Issuer's common stack upon vesting (or upon election by the reporting person, up to 50% of the RSUIs in cash).

Not applicable. Each RSU represented the right to receive one share of the Issuer's common stock upon vesting (or upon election by the reporting person, up to 50% of the RSUs in cash).

Not applicable. The reported shares were acquired in connection with the vesting of a restricted stock unit (RSU)award.

Not applicable. Each RSU represented the right to receive one share of the Issuer's common stock upon vesting (or upon election by the reporting person, up to 50% of the RSUs in cash).

Not applicable. The reported shares were acquired in connection with the vesting of a restricted stock unit (RSU) award.

Not applicable. Each RSU represents the right to receive one share of the Company's common stock upon vesting without payment.

Not applicable. Represents shares acquired in connection with the vesting of a Restricted Stock Unit ("RSU") award.

Not applicable. Each RSU represents the right to receive one share of the Company's common stock upon vesting without payment.

Not Applicable. Each RSU represents the right to receive one share of Common Stock upon vesting without payment.

Not Applicable. The acquisition reflects an award of Restricted Stock Units pursuant to the Company's 2019 Equity Incentive Plan. The award vests in one-third annual increments beginning on March 12, 2027, assuming continuous service by the Reporting Person during each vesting increment, subject to accelerated vesting under certain circumstances.

Not Applicable. Each RSU represents the right to receive one share of Common Stock upon vesting without payment.

Not Applicable. The acquisition reflects an award of Restricted Stock Units pursuant to the Company's 2019 Equity Incentive Plan. The award vests in one-third annual increments beginning on March 12, 2027, assuming continuous service by the Reporting Person during each vesting increment, subject to accelerated vesting under certain circumstances.

The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $37.1538 to $37.3455 inclusive. The reporting person undertakes to provide to NGS, any security holder of NGS, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $37.30 to $38.5596 inclusive. The reporting person undertakes to provide to NGS, any security holder of NGS, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

Shares acquired through reinvestment of cash dividends pursuant to the terms of the deferred compensation plan.

Shares acquired through reinvestment of cash dividends pursuant to the terms of the deferred compensation plan.

Not applicable. Each RSU represents the right to receive one share of the Company's common stock upon vesting without payment.

Not applicable. Represents shares acquired in connection with the vesting of a Restricted Stock Unit ("RSU") award.

Not applicable. Represents shares acquired in connection with the vesting of a Restricted Stock Unit ("RSU") award.

Not applicable. Each RSU represents the right to receive one share of the Company's common stock upon vesting without payment.

The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $33.50 to $33.72 inclusive. The reporting person undertakes to provide to NGS, any security holder of NGS, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $33.015 to $33.45 inclusive. The reporting person undertakes to provide to NGS, any security holder of NGS, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $31.83 to $32.28 inclusive. The reporting person undertakes to provide to NGS, any security holder of NGS, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

Shares acquired through reinvestment of cash dividend pursuant to the terms of the deferred compensation plan.

Shares acquired through reinvestment of cash dividend pursuant to the terms of the deferred compensation plan.