5-piece bolt-grip set. Removes rounded off, painted over, damaged and rusted over nuts, and bolts. Set includes 3/8", 7/16"/11mm, 1/2", 9/16"/14mm, and 5/8"/16mm. Can be used on a 3/8" ratchet, impact wrench, or air ratchet. Base of socket is hex to allow use of flat wrenches, box wrenches, adjustable wrenches, or locking pliers. Fits both metric and standard sized nuts and bolts. 6T of high-carbon steel-grip tight to remove the nut or bolt. Storage case.