Circular Safecase Master Test gauge, serial no. Z81747, 6.25″ in diameter, made by the Marsh Instrument Company. Gauge is calibrated from 0 to 6000, has a NASA/KSC label affixed to the face, and a NASA KSC Cleaned label, dated September 17, 1983, affixed to the glass cover. The two calibration seals on the reverse are worn, but remain intact. In fine condition.
