Made for the most demanding professionals, each of our sockets is made from custom forged premium steel that underwent proprietary heat treatment and precisely machined to perform in toughest situations Premium Chrome Vanadium steel tempered with our proprietary heat treatment process to withstand more torque SmartKrome plating, achieved through thorough polishing and careful application of chrome protective plating, ensures durability and corrosion resistance WaveDrive design grips fasteners more tightly than traditional design, preventing fastener rounding and giving you more leverage Come with our premium double-sided socket rail with detent ball spring clips to keep the socket bits securely organized. (13) external star sockets: 1/4 in. drive: E4, E5, E6, E7, E8, 3/8 in. drive: E10, E12, E14, E16, 1/2 in. drive: E18, E20, E22, E24, Manufacturer: Capri Tools