The TE Connectivity 213813-1 is a coupling nut — the threaded ring that secures a CPC connector pair — not a housing or insert. It belongs to the CPC (Circular Plastic Connector) series and is sized for shell size 13 inserts. The black nylon body provides a non-conductive, corrosion-resistant grip for hand-tightening the connector halves together.
This coupling nut mates with any TE CPC connector that uses a shell size 13 interface — the standard diameter for medium-density circular connectors in the CPC family. It does not carry contacts or seal the connector; its job is to draw the plug and receptacle together and hold them under vibration. The thread size is specific to the shell size 13 design, so it will not fit other shell sizes in the CPC range.