What sets the M4 RAS apart from other two-piece quad rails in the marketplace is it securely locks towards the rifle’s barrel nut by using a clamp and screw arrangement, which makes it an exceptionally stable foundation upon which to mount tactical components. Features 3 KAC eleven Rib Rail Panels. https://tysonznxir.pointblog.net/indicators-on-knights-armament-m4-quad-rail-you-should-know-67710050