The 206554-1 is a reverse numbering circular plug with a 17-16 contact arrangement, part of the AMP Circular Plastic Connector (CPC) series. Its housing is constructed from a lightweight, black thermoplastic with a UL 94V-0 flammability rating, suitable for an operating temperature range of -40°C to +105°C. This shell size 17 plug is designed to accept 16 Size 16 socket contacts (ordered separately) and features a 15/16-20 UNEF-2A threaded coupling for secure mating. It is specifically designed to mate with the 206552-1 feed-thru receptacle, making it ideal for commercial signal and power applications requiring a panel passthrough.