PRLB

Reflects the weighted average price of 1,500 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on June 2, 2026, with sale prices ranging from $76.86 to $77.00 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

25% of shares subject to the award will vest on May 20, 2027, and on each May 20th thereafter until all shares subject to the award are fully vested.

Restricted Stock Units that vest as follows: 25% of shares subject to the award will vest on May 20, 2027, and on each May 20th thereafter until all shares subject to the award are fully vested.

Deferred stock units that vest in full on the earlier of the first anniversary of the grant date or the date of the 2027 Annual Meeting of Shareholders but must be retained until the reporting person's service on the Company's Board of Directors ends.

Deferred stock units that vest in full on the earlier of the first anniversary of the grant date or the date of the 2027 Annual Meeting of Shareholders but must be retained until the reporting person's service on the Company's Board of Directors ends.

Deferred stock units that vest in full on the earlier of the first anniversary of the grant date or the date of the 2027 Annual Meeting of Shareholders but must be retained until the reporting person's service on the Company's Board of Directors ends.

Restricted stock units that vest in full on the earlier of the first anniversary of the grant date or the date of the 2027 Annual Meeting of Shareholders.

Deferred stock units that vest in full on the earlier of the first anniversary of the grant date or the date of the 2027 Annual Meeting of Shareholders but must be retained until the reporting person's service on the Company's Board of Directors ends.

Deferred stock units that vest in full on the earlier of the first anniversary of the grant date or the date of the 2027 Annual Meeting of Shareholders but must be retained until the reporting person's service on the Company's Board of Directors ends.

25% of shares subject to the award will vest on February 13, 2024, and on each February 13th thereafter until all shares subject to the award are fully vested.

Reflects the weighted average price of 4,198 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $68.10 to $69.0425 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

25% of shares subject to the award will vest on February 25, 2026, and on each February 25th thereafter until all shares subject to the award are fully vested.

Reflects the weighted average price of 1,613 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $67.06 to $68.05 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

25% of shares subject to the award will vest on February 13, 2023, and on each February 13th thereafter until all shares subject to the award are fully vested.

Reflects the weighted average price of 6,643 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $70.13 to $70.57 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

Reflects the weighted average price of 3,576 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $69.13 to $70.1181 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

25% of shares subject to the award will vest on February 13, 2025, and on each February 13th thereafter until all shares subject to the award are fully vested.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

25% of shares subject to the award will vest on February 13, 2024, and on each February 13th thereafter until all shares subject to the award are fully vested.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

Reflects the weighted average price of 7,433 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 11, 2026, with sale prices ranging from $70.00 to $70.57 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

25% of shares subject to the award will vest on February 13, 2025, and on each February 13th thereafter until all shares subject to the award are fully vested.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

25% of shares subject to the award will vest on February 13, 2024, and on each February 13th thereafter until all shares subject to the award are fully vested.

These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.

25% of shares subject to the award will vest on February 25, 2027, and on each February 25th thereafter until all shares subject to the award are fully vested.

25% of shares subject to the award will vest on February 25, 2027, and on each February 25th thereafter until all shares subject to the award are fully vested.

Restricted Stock Units that vest as follows: 25% of shares subject to the award will vest on February 25, 2027, and on each February 25th thereafter until all shares subject to the award are fully vested.

Restricted Stock Units that vest as follows: 25% of shares subject to the award will vest on February 25, 2027, and on each February 25th thereafter until all shares subject to the award are fully vested.

25% of shares subject to the award will vest on February 25, 2027, and on each February 25th thereafter until all shares subject to the award are fully vested.

25% of shares subject to the award will vest on February 25, 2027, and on each February 25th thereafter until all shares subject to the award are fully vested.

Restricted Stock Units that vest as follows: 25% of shares subject to the award will vest on February 25, 2027, and on each February 25th thereafter until all shares subject to the award are fully vested.

Restricted Stock Units that vest as follows: 25% of shares subject to the award will vest on February 25, 2027, and on each February 25th thereafter until all shares subject to the award are fully vested.

This transaction was executed pursuant to a Rule 10b5 1 trading plan adopted by the Reporting Person on August 15, 2025.

Reflects the weighted average price of 5,000 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on February 17, 2026, with sale prices ranging from $66.01 to $66.87 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

Fully vested.