Two rail. I have shot 18s with rifle fuel like how easy and exact They are really. I can set extra money into functionality areas then clone right parts like a ops brake and collar that I don't have a can for. Posted by BRAD on 23rd Jan 2020 Amazing https://knights-armament-m4-quad08518.losblogos.com/29013369/fascination-about-m4-ras-rail