Combat Armory Manufacturing Mil Spec AR15 stripped Upper Receiver. Made of 7075 T6 Aluminum Billet. Features M4 Feed Ramps Hard Anodized Black Can be used for Multiple Calibers on the AR15 Platform. This Upper is Machined to the Mil Spec. Combat Armory machinist take pride in delivering the very best for our customers used by Military, Police, and Firearms enthusiasts.