Lightweight Threaded Plugs - NH MaleLightweight Threaded Plugs NH Male Threaded adapters available from 1. 5 to 6. All adapters provide the necessary safety features for municipal fire fighting. Storz adapters 4 and larger feature a Storz Lok locking mechanism. All threaded adapters are hard coated to military spec. Type 3 and made from aircraft #6061 T light weight aluminum. All female swivels utilize stainless steel ball bearing or aluminum roller bearings, no plastic. Available