Gemtech 5.56mm Muzzle Brake 1/2-28 Thread 845F45B7 MO. Features of Gemtech 5.56mm Muzzle Brake 1/2-28 Thread: Quickmount lugs for use with all 5.56mm and 7.62mm suppressors Blank Firing Adapter (BFA) groove for use with GM/GMT-HALO and training devices Increased size of 3/4" wrench flats for installation Extended portion behind lugs for use on shorter barrels Precision mounting shim kit included Package Contents: Gemtech 5.56mm Muzzle Brake 1/2-28 Thread The GEMTECH Muzzle Brake is for users who want less felt recoil less muzzle climb and faster follow up shots. MO12152