Features: 1.Using high?quality chromium vanadium steel materials carefully manufactured and designed to improve torgue and unparalleled hardness. 2.The hardened socket can effectively increase the rotation power and reduce wear. 3.It has complete anti?rust and corrosion resistance, is not easy to damage, and can be used for a long time. 4.The end of the drill bit with precise chamfer can be inserted smoothly, and the size is printed on the socket for easy access. 5.It has a wide range of applications and can be used in households and automobiles. It is convenient and highly practical. Specification: Item Type: Hex Key Wrench Bit Socket Set Material: Chromium Vanadium Steel Toolbox Color: Blue Toolbox Size: Approx. 220x113mm/8.7x4.4in Square Wrench Interface Size: 3/8 inch Hex Bit Size: H3, H4, H5, H6, H7, H8, H10 (H in the hexagonal bit size also means millimeters, which is a diagonal size, such as H3 is equal to 3mm, and so on) Total Length of Hex Bit: Approx. 110mm/4.3in (Due to manual measurement, there may be a deviation of 1-2 mm) Application: Suitable for 3/8 inch square wrench interface/air wrench/power rod Usage: For Household, automotive using PackageList: 7 x Socket Bit 1 x Toolbox