This listing is for one replacement key, model D4DS-K2, intended for use with D4NS-series safety-door/safety-interlock switches. The D4DS-K2 uses a vertical-latch key profile and is referenced by distributor/catalog listings for D4NS family service parts. It is supplied as a single key for maintenance or parts replacement. Because switch housings and key variants can differ across submodels, please confirm your switch accepts a D4DS-series key before ordering.