The "Claw" is the perfect armorer tool for holding all AR-15 & M-16 upper receivers. Made of a solid one piece high strength polymer, the Claw is extremely durable. Simply clamp the Claw into a bench vise, slide the upper onto the Claw, secure with the two holding pins and begin installing your barrel and components. This tool is a must have from the work of an Armorer, to an avid Sportsman installing an Optic or scope.