SilencerCo AC1360 Thread Protector 9mm Luger Black Steel 1/2"-28 tpi AR-Platform
When transporting your firearm, keep your threads crisp and protected with a thread protector. Careful not to cross-thread, simply twist the thread protector on the end of your barrel to prevent dust and debris from clogging your threads when no silencer is in use. 1/2" X 28 is compatible with most US-made 9mm.