Due to the extra-thin wall design, they should only be used on wheel nuts where limited torque is applied For use only with 1/2" drive tools DO NOT use reducing adapters Extra-thin wall impact sockets are not covered by the Grey Pneumatic Warranty This set contains both fractional and metric. Each socket is designed with the extra-thin wall design. This allows easy access to recessed wheel nuts where space is limited. Set contains the following sizes: 3/4", 13/16", 7/8", 1", 1-1/16" and a 3/4" x 13/16" Flip Socket and 17mm, 19mm, 21mm, 22mm, 23mm and a 19mm x 21mm flip socket. Packaged in a molded storage case.