"The FN USA FN15 Military Collector M16 Semi-Auto Rifle is a civilian-legal reproduction on the US Military's M16 Rifle. Built to legit mil-spec standards and featuring the Knight's Armament M5 RAS adapter rail, this is a straight-to-business battle rifle. The Military Collector M4 has a 20"", button-broached, chrome-lined barrel topped off with the trusty A2 flash hider. The flat top receiver on the M4 is ready for an optic and comes with a flip-up rear sight. The carbine-length gas system features an A2 front-sight gas block. The FN USA Military Collector's KAC rail is also topped off with a KAC rail panel kit and KAC foregrip. A classic, fixed A2 stock contains the receiver extension and buffer system. An ambidextrous safety selector simplifies things when shoulder transitions are in play. If you're looking for a truly battle-proven setup with throw-back vibes that will have zero issues keeping up with modern rifles, the FN 15 Military Collector M16 is your guy. 20"" barrel 1:7 twist A2 Flash hider Knights Armament M5 RAS Adapter Rail adapter covers and forgrip Flat-top upper receiver Rear flip-up sight A2 front sight gas block Fixed A2 stock Ambi safety selector A2 pistol grip"