The SRD556Ti-QD is a Grade 5 Titanium silencer using fast-attach muzzle devices to mount the silencer to the rifle. The 1/2"x 28tpi threads match the vast majority of modern sporting rifles in .223/5.56mm on the market today. The rear mount has wrench flats to torque the silencer to the barrel. There is a secondary retention latch that is depressed to remove the silencer from the fast-attach mount. The SRD556Ti-QD comes with one 1/2"x 28tpi Taper-Lok™ muzzle brake. 134 dB rated. Made of Grade 5 Titanium.