The CLASSIC ARMY URX4 8″ KEYMOD M4 (Flash Magazine Included) (Full Metal) The CA081M is an M4 Carbine equipped with a URX4 style front handguard. The URX is the next evolution of the RAS system pioneered by Knights Armament Corp. The KeyMod version utilizes the open-source design originally pioneered by Noveske and VLTOR. The unit comes with front and rear “flip-up” backup sights, allowing the use of optics, but retaining iron sights in emergencies. Multi-position “CRANE” stock allows for a better cheek weld, Tango Down styled pistol grip is more comfortable than standard AR-15 grip. Classic Army “Flash mag” allows the airsofter to deploy maximum firepower with minimum effort.