Five straight longitudinal vents hide flash while dispersing gases outward to tame muzzle rise. No downward facing port helps eliminate dust signature when shooting in the prone position. For threaded barrels only, includes a crush washer. Specs: Steel, mil-spec phosphate coating. .223 caliber, 1/2-28 tpi. 2-1/4 in long, 7/8 in diameter. Weight: 2.1 oz (60 g).