Rock River Arms CAR A4, Semi-automatic, AR, 223 Remington/556NATO, 16 Barrel, A2 Flash Hider, Adjustable Gas Block, Black, A2 Grip, 6 Position Collapsible, Carbine Length Handguard, 30 Rounds, Two Stage Trigger, 1 Magazine, Includes Case AR1850 The Rock River Arms CAR A4 is well equipped for general duty use. It features a 16" chrome moly barrel, carbine-length gas system, RRA Two Stage Trigger, carbine length handguard, 6 position stock, and weighs in at 7.1 lbs.