The AR-STONER Upper Vise Block is made of Solvent resistant polymer construction for strength & durability. It allows for safe clamping and will help to prevent any type of distort or damage to the Upper receiver. Great to use when performing your regular maintenance, repairs or weapon assembly. Fits most standard Mil-Spec AR-15/M4 style rifles FeaturesLength: 4.75"Net Weight: 14.1 oz.Color: Black