TacFire Tanker Muzzle Brake Black Oxide Steel With 1/2"-28 tpi Threads 2.76" OAL 1.37" Diameter For 5.56X45mm Nato Tanker Style Muzzle Brake Is Made Of All Steel Construction With a Heat Treated, Erosion Resistant Black Oxide Finish. It Comes With a .308 1/2"X28 Thread Pitch. Reduces Recoil And Barrel Whip. This Brake Is Perfect For Rifles Threaded In 1/2"X28 Thread Model: Tanker Muzzle Brake Material: Steel Thread Pattern: 1/2"-28 tpi Finish: Black Oxide