This replica is full metal and features moving parts and blowback to simulate firing.
 
This platform is modular and has many stocks, supressors, sights and other accessories available.
 
The Close Quarter Battle Receiver (CQBR) is a replacement upper receiver for the M4A1 Carbine, developed by the US Navy. The CQBR features a barrel 10.3 in (262 mm) in length, similar to the Colt Commando short-barreled M16 variants of the past.