X0609 4 2026-10-13 0 0000724004 MESA LABORATORIES INC /CO/ MLAB 0001305784 Sullivan John James false 12100 W. 6TH AVENUE LAKEWOOD CO 80228 1 0 0 0 0 Common Stock 2026-10-13 4 G 0 1200 0 D 19418 D Common Stock 45110 I By Trust Represents shares held by the "Sullivan Family Trust" for which the reporting person's spouse serves as Trustee. The reporting person disclaims beneficial ownership of the securities held by the trust except to the extent of his pecuniary interest therein John Sakys under Power of Attorney by John Sullivan 2026-10-29