It has very high friction resistance, which improves the service life of the drill bit group and not damage the screws. Each head group is designed accurately to the cooperation and stability with various screws. characteristic: Made of high quality metal, it has excellent hardness and durability. All tools are packed in portable storage boxes, which are easy to carry and store. Used for electric screwdrivers, manual screwdrivers, electric drills, pneumatic tools and pneumatic drills. It is an Perfect repair tool for repairing household appliances, instruments and furniture., Manufacturer: PokFhgur