Neat looking item from X-Fire/PDI and something you want installed as muzzle/flash hider for your M4/M16 series... "This is U.S.Troy industry type hider.Made of Duralmin.If you have M14,please use "PDI-M14 Troy type attachment". We have just 14mm Negative. This muzzle has small screw and You can adjust the Hider's angle and keep best position. This muzzle has pointed front. Be careful."