The GTCL03028-21P(025)(B30) from Amphenol Industrial Operations is rear panel mount circular connector, receptacle with male pins, 37 position, shell size-insert 28-21 and crimp termination (with low smoke/flame retardant inserts). This environment proof (when mounted with a proper sealing gasket) connector has reverse bayonet coupling, threaded rear (to accept accessory attachment) and square flange. The GTCL03028-21P(025)(B30) has copper alloy contacts with gold/nickel finish and aluminum alloy shell with black zinc cobalt finish. Operating temperature range is from -55°C to 125°C.