Via Clarkson Online:

It weighs 3.5 pounds, has a barrel length of 7.75 inches, fires 12-gauge shells and can be mounted on the M4 carbine or act as a stand alone firearm; it is the M26 Modular Accessory Shotgun System and the 2nd Brigade Combat Team, 101st Airborne Division (Air Assault) is the first unit in the Army to be issued the combat enhancer.