The MS3102A28-21P from Amphenol Industrial Operations is box mount circular connector (MIL-DTL-5015 type), receptacle with male pins, 37 position, 28-21 insert arrangement, threaded fastening and solder cup termination. Comes with solid shell for general, non-environmental applications. This connector has copper alloy contacts with silver finish, neoprene insert and aluminum alloy shell with olive drab chromate over cadmium finish. Operating temperature range is from -55°C to 125°C.