No amount of accurizing will make a 1911 Auto shoot wadcutter ammo if the magazine's feed lips aren't right. These tools easily reform the lips to the optimum angle, curing the tendency of wadcutters to jam against the ramp. "Anvil" fits inside the magazine and establishes the angle. "Yoke" (designed by Lou Woll while at Rock Island Arsenal) fits over the lips and ensures that both sides will be identical. Mfg: Brownells SPECS: 1018 Steel, hardened to Rc 50. Anvil - 2¾" (70cm) x 1¼" (3.2cm) x 3/8" (9.5mm). Yoke - 3" (7.6cm) x 1" (2.5cm) x 5/8" (41.2mm). Set includes one of each. Instructions included.