Applies to the screwdriver handle or electric screwdriver tools (hexagonal hole or three jaw chuck),After the installation of the hexagonal connector can be converted to square, which can be used for the sleeve installation, conversion tool. Chrome Vanadium Steel is hard enough for home use The spring ball lock prevent slipping during working. Perfect for pneumatic screwdriver, electric screwdriver, pneumatic drill, manual screwdriver and other installation for the hexagonal tool .It is a good accessory for conversion Different colour coded rings, make it easy to pick the right one., Manufacturer: HALJIA