Features： 1、High temperature quenching, resistant to rust and corrosion, rugged and durable, strong torsion. 2、The hardened chrome‑vanadium steel socket improves rotation efficiency and reduces wear. 3、There is a precise chamfer at the end of the bit, which can be inserted smoothly. 4、The size is printed on the socket for easy identification, bring much convenience for you. 5、Including a variety of bits with different specifications, completely meet your different needs. Specification： Item Type: Wrench Socket Bit Material: Chrome-Vanadium Steel Square Wrench Drive Size: 1/2in, 3/8in Specifications of Hex Bits: T20 T25 T30 T40 T45 T50 T55 (length: approx. 30mm/1.2in) T20 T25 T30 T40 T45 T50 T55 (length: approx. 75mm/3in) H4 H5 H6 H7 H8 H10 H12 (length: approx. 30mm/1.2in) H4 H5 H6 H7 H8 H10 H12 (length: approx. 75mm/3in) M5 M6 M8 M10 M12 (length: approx. 30mm/1.2in) M5 M6 M8 M10 M12 (length: approx. 75mm/3in) Quantity: 40pcs/set Suitable for: 1/2in and 3/8in square wrench drive/air impact wrench/power rod, etc. Application: Household, automobile, etc. Package List： 40 x Bits 1 x Tool Box