The AR-15 shark muzzle brake and crush washer for sale is is designed for your .233, 5.56 AR Rifle and pistols with 1/2x28 thread pitch on barrel. Muzzle brake is CNC Machined High Quality Steel with military style black oxide finish. Top and sides are ported to reduce back pressure and recoil. This muzzle brake has 5/8"-24 thread pitch and comes with black crush washer. Length: 2.87 inches. Muzzle brake features an aggressive six prong design for an improvised breaching and impact device for hand-to-hand combat situations. Crush Washer Included. One year limited warranty.