Silencerco 1/2x28 Delta Thread Protector - When transporting your firearm or waiting on ATF approval, keep your threads crisp and protected with a thread protector. Be careful not to cross-thread, simply twist the thread protector on the end of your barrel to prevent dust and debris from clogging the threads when no silencer is in use. Compatible With The Switchback 22, Sparrow 22, Spectre 22, Warlock 22 And Osprey Micro 22 Suppressors