Detailed Product Description 20Pc Hex Key Set Set contains heat treated carbon steel AF and MM keysIncludes 10 black finished keys & 10 zinc plated keysSize: 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 5mm, 5.5mm, 6mm, 8mm (1/16",5/64", 3/32", 1/8", 5/32", 3/16", 7/32", 15/64", 1/4", 5/16")