Set of 9 fixed keys. chrome-vanadium steel, chrome plated. heat treated and tempered to meet or exceed ansi standards for strength and durability. matte finish. size o: 6-7 mm, 8-9 mm, 10-11 mm, 12-13 mm, 14-15 mm, 16-17 mm, 18-19 mm, 20-22 mm, 21-23 mm