IMPACT-RESISTANT: This 13 piece 1/2" square drive socket set is made from drop-forged, chrome vanadium impact grade steel with a black finish. DURABLE AND HARDWEARING: They are durable with a hardwearing black electrophoretic finish. SIZES: The square drive sockets come in the following sizes: 11mm, 12mm, 13mm, 14mm, 16mm, 17mm, 19mm, 21mm, 22mm, 24mm, 27mm, 30mm & 32mm. ESSENTIAL PRODUCT: It is the ideal product for use with pneumatic, cordless or corded high torque impact wrenches. STORAGE CASE SUPPLIED: The sockets are supplied in a sturdy metal storage case. Contents: 11mm, 12mm, 13mm, 14mm, 16mm, 17mm, 19mm, 21mm, 22mm, 24mm, 27mm, 30mm, 32mm, .