Will not mark or scratch expensive or delicate firearm parts, but holds them firmly without damage. Durable, nylon-reinforced rubber is permanently bonded to lightweight aluminum, replaceable jaws. Wide retaining lip with nitrile magnet on the underside keeps jaws in place; drops right onto any 4", 5" or 6" steel bench vise and stays put. Mfg: Brownells SPECS: Aluminum jaws, rubber face. 4" (10cm) long, 3/8" (9.5mm) thick, 1¼" (3.8cm) wide face.