 It is similar to, but uses a different mounting system than the Knight's Armament Company Masterkey or the accessory weapon configuration of the Remington 870 MPS.The system consists of a modified shotgun mounted on a M16 or M4 assault rifle, in an underbarrel configuration, much like the M203 grenade launcher.The method of attachment differs in that the Ciener system attaches to the host weapon using a yoke adapter to join the receivers of both weapons and an adaptor to join the shotgun's barrel to the rifle's bayonet lug.