Form 4 Filing for Michele M. Leonhart

Michele M. Leonhart, a director at 908 Devices Inc., reported several transactions on June 10-11, 2026. These include the disposition of 14,083 Restricted Stock Units (RSUs) that vested on June 10, 2026, and the acquisition of 13,656 RSUs and 6,209 stock options on June 11, 2026. The RSUs represent contingent rights to receive common stock upon vesting. The stock options become exercisable over 12 months following June 11, 2026. Additionally, there was a non-derivative transaction involving the acquisition of 14,083 shares of Common Stock on June 10, 2026, resulting in 20,568 shares held post-transaction. The filing also includes a Power of Attorney document authorizing Kevin J. Knopp, Joseph H. Griffith, and Mark S. Levine to execute SEC filings on behalf of the reporting person.