This A1 3.5" muzzle brake/flash hider is perfect if you want to add some length to a short barreled rifle project or are looking for a different look for your AR. It is a machined, ported muzzle brake with locking notches to prevent any movement while under fire. Actual item may have more ports than shown in photos. It is threaded 1/2x28 for the AR-15, works for .223, 5.56 & 9mm. It can be pinned and welded for compliance as well. Weighs about 5 ounces.