This tri-lug adapter gives you the ability to quickly attach a sound suppressor when shooting suppressed. Featuring a universal 3-lug interface this 3-lug muzzle device can quickly interface with any pistol caliber sound suppressor as well as the Angstadt Arms 3-Lug QD Blast Shield! Made from hardened steel with a black nitride finish Does not require the use of shims. Shims can be used if specific timing is desired. Do not use a crush washer Available in 1/2A-28 thread pitch 1.42a ^2 long 0.9 oz