1. Chrome vanadium steel suitable for heavy duty impact drivers. Spring loaded ball bearing on head holds sockets securely. 2. This set is perfect for your impact driver or drill, and allows you to replace your ratchet with a power tool. 3. Suitable for a screwdriver or electric screwdriver handle tools (hexagonal hole or three-jaw chuck can) drive sleeve and after use can be installed on the size of the original hexagonal polygons converted to square head size, which can be used to install the sleeve is a good accessory to convert.
