Designed in the JP Enterprises custom shop, the Vise Clamps are used to assembly JP's own AR-15 and large frame, AR style rifles. Installing and removing barrels or handguards on an AR upper is a breeze with these handy vise jaws. Designed for flat-top uppers, these clamps capture the top rail and receiver lugs to prevent damage to the receiver. Integral magnets hold the vise clamps to the existing jaws of your bench vise, then simply clamp the upper receiver in for a rock solid platform. The different sized cutouts in either end will accept the front pivot pin lug of either small or large AR receivers.