Manufactured from Chrome Molybdenum steel with manganese phosphate finish for added corrosion resistance. Features specially machined flutes in the walls of the socket to enable use on up to 85% rounded fasteners. Suitable for use with air/electric impact guns. Sizes: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 24mm. Supplied in storage case. Lifetime guarantee*. Model No. AK5616M