Angstadt Arms 3-Lug Muzzle Adapter, 9MM, 1/2x28, Nitride Finish, Black AA093LSD28 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!