This specification covers only the Cooler-Dewar Group to be used in the M 1 Thermal Imaging System(TIS). The Cooler-Dewar Group is a component of the Thermal Imaging Systems(FLIR) used in the M1. The group consists of a 120 element infrared detector DT-617A/üA, a one watt cryogenic cooler,(HD-l033B/UA, HD-1033CAJA or HD-l033D/UA), a thermal conductor and associated fastening hardware.