NPKI · NPK International Inc.

Represents pro-rated portion of non-employee director's annual equity retainer. The shares will vest on the earlier of the first anniversary of the date of grant or the day priopr to the next annual stockholders meeting.

The reported sale of 8,325 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 15, 2025.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.40 to $15.03, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported sale of 167,375 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 4, 2026.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.29 to $14.56, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported sale of 10,446 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 15, 2025.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.33 to $14.74, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

The restricted stock units vest and convert into shares on a one-for-one basis.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

The restricted stock units vest and convert into shares on a one-for-one basis.

Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

The restricted stock units vest and convert into shares on a one-for-one basis.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

The restricted stock units vest and convert into shares on a one-for-one basis.

Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

The restricted stock units vest and convert into shares on a one-for-one basis.

Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

The restricted stock units vest and convert into shares on a one-for-one basis.

The restricted stock units vest and convert into shares on a one-for-one basis.

Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

The restricted stock units vest and convert into shares on a one-for-one basis.

Represents shares withheld to satisfy tax withholding obligations upon the vesting of restricted stock units.

The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

The shares will vest on the earlier of the first anniversary of the date of grant or the day prior to the next annual stockholders meeting.

Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

Grant of restricted stock units that vest in one-third increments on June 1 of each subsequent year after grant and settle in shares.

The reported sale of 2,013 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $15.21 to $15.54, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported sale of 15,000 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $15.00 to $15.10, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported sale of 35,000 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.33 to $14.68, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported sale of 15,000 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $15.00 to $15.12, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported exercise of 1,000 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 5, 2025.

The reported exercise of 1,000 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 5, 2025.

These options were sold on the open market at price stated. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of options sold.

The reported exercise of 1,000 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 5, 2025.

The reported exercise of 11,193 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 5, 2025.

The price reported is the weighted average price. These options were sold in multiple transactions in the open market at prices ranging from $13.24 to $13.48, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of options sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported exercise of 11,193 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 5, 2025.

The reported exercise of 11,193 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 5, 2025.

The reported exercise of 73,590 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

The reported sale of 35,000 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $13.68 to $14.31, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported exercise of 73,590 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

The price reported is the weighted average price. These options were sold in multiple transactions in the open market at prices ranging from $14.00 to $14.31, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of options sold at each separate price within the range set forth in footnote (2) to this Form 4.

The reported exercise of 73,590 options and subsequent sale of the shares acquired upon exercise occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 3, 2025.

The reported sale of 2,013 shares occurred automatically pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 7, 2025.

The price reported is the weighted average price. These shares were sold in multiple transactions in the open market at prices ranging from $14.11 to $14.43, inclusive. The reporting person undertakes to provide to NPK International Inc., any security holder of NPK International Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (2) to this Form 4.