Product Description TacFire's Thread Crown muzzle break is constructed of steel and made in the USA. This 223/5.56 model has 1/2"x28 tpi and a black oxide finish. TacFire MZ1021 Thread Crown Muzzle Brake Black Oxide Steel with 1/2"-28 tpi Threads & 2.05" OAL for 5.56x45mm NATO AR-15 at United States Association of Gun Owners Browse all United States Association of Gun Owners deals $16.93 In Stock at United States Association of Gun Owners Price verified 2d ago Buy Now at United States Association of Gun Owners Secure checkout Easy returns or compare prices Amazon eBay Product Details Brand United States Association of Gun Owners United States Association of Gun Owners