NIB.  The Midwest Industries .30 cal muzzle brake, has a three chamber design to significantly reduce muzzle rise. It is constructed of tool steel with a phosphate finish. The threading is 5/8 - 24 designed for .30cal/.300 AAC rifles. The muzzle brake weighs 4oz, includes a new crush washer, and is 100% MADE IN THE U.S.A.