A heavy-duty clamp for gunsmithing, maintenance or cleaning your mil-spec A2 uppers and flat-top receivers. Safely clamps onto your AR-15 upper receiver and holds it securely without twisting, crushing or marring the finish of your rifle. High-pressure, solvent-resistant polymer construction. Includes handy receiver insert with a gas-tube alignment system. Fits left- and right-hand receivers. Dimensions: 15"H x 7"W x 2"D.