The WM-12P is a Wedgelock made of orange thermoplastic. The DTM series wedgelock is fits to all DTM04-12P receptacles. The wedgelock ensures proper contact alignment within each connector. The secondary wedgelock is assembled at the mating interface and click into place. If by chance the secondary wedgelocks is not properly seated during assembly, it will be pressed into locked position during the mating of the connectors.