Specification: 13 pieces of damaged rusty nut and bolt removal sleeve Material: chrome molybdenum steel Features: A 13-piece set of 3/8 ’’ opening reverse screw damaged / rusty nut screw removal sleeve. The reverse spiral groove provides maximum grip for easily removing damaged or rusted nuts, bolts and screws. Chromium molybdenum steel provides longer life and durability. Universal leaflet design is suitable for all types of fasteners. Packing list: 1/4 “, 5/16 " (8 mm), 3/8 " 10 mm, 7/16 " (11 mm), 12 mm, 1/2 “, 13 mm, 9/16 " (14 mm), 5/8 " (16 mm), 17 mm, 11/16 “, 3/4 " (19 mm)