Faxon AR-15 ARAK-21 Upper Receiver Assembly 5.56x45mm NATO 12.5" Barrel

The Faxon ARAK-21 is a gas piston actuated, complete upper receiver assembly designed to seamlessly interface with the standard AR-15 platform. The total extent of the interface is simply the take down pin, and the pivot pin. The ARAK-21 upper receiver offers you all its features with no change to your current lower receiver and can be installed in less than one minute with no tools. The BAU is comprised of the barrel, gas block, muzzle brake, gas piston, gas adjuster, and barrel trunnion. The