Griffin Armament Taper Mount Thread Protector. Not for use with M4SD or 30SD (SDQD Muzzle Devices) These are not required for operation but many consider them nice to have. Suppressor mounts included with suppressors do not include thread protectors. Thread protector has taper mount interface and does not shoot loose. Specifications for Griffin Armament Thread Protector for Taper Mount Muzzle Device: Manufacturer: Griffin Armament Condition: New Package Contents: Griffin Armament Thread Protector for Taper Mount Muzzle Device Griffin Armament TMTP: Taper Mount Thread Protector