What this coupling ring is and what it does
The TE Connectivity 213812-1 is a coupling ring for the CPC (Circular Plastic Connector) series, Shell Size 23. It is the threaded collar that secures the plug to the receptacle — you spin it down to lock the connector pair, not a signal-carrying component. The ring is molded in black nylon, which gives it the chemical resistance and impact toughness needed for industrial environments where connectors get yanked, splashed, and cycled repeatedly. This is an accessory, not a connector body: it mates with CPC connectors of the same Shell Size 23, so if you are building a harness, confirm your plug and receptacle both use the 23 shell before ordering this ring.