X0306 4/A 2021-09-23 2021-09-24 false 0001555279 908 Devices Inc. MASS 0001608021 Basarsky Trent A. C/O 908 DEVICES INC. 645 SUMMER STREET BOSTON MA 02210 false true false false VP, Corporate Development Common Stock 2021-09-23 4 M false 6000.00 1.75 A 41000.00 D Common Stock 2021-09-23 4 S false 2128.00 37.09 D 38872.00 D Common Stock 2021-09-23 4 S false 3872.00 38.04 D 35000.00 D Stock Option (Right to Buy) 1.75 2021-09-23 4 M false 6000.00 0.00 D 2027-04-26 Common Stock 84504.00 78504.00 D Represents sales effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $36.59 to $37.56, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices 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 ranges set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $37.76 to $38.38, inclusive. The reporting person undertakes to provide to 908 Devices Inc., any security holder of 908 Devices 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 ranges set forth in this footnote. The shares underlying the option are fully vested and immediately exercisable. The original Form 4, filed September 24, 2021, is being amended by this Form 4 amendment solely to correct an administrative error. This Form 4 includes the exercise of 6,000 stock options in Table II, and the related acquisition of 6,000 shares of common stock in Table I. This Form also corrects the total number of shares of common stock beneficially owned by the reporting person subsequent to the reported transactions in Table I. /s/ Michael S. Turner, as Attorney-in-Fact 2021-09-27