mobarel - Impact socket adapter set, Cr-Mo Content: Impact Socket 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 27, 30 MM; O-RING x 2; PIN x 2 Chrome Molybdenum Alloy Steel (Cr-Mo) for Exceptional Strength and Durability Manganese Phosphate Coating to Resist Corrosion