High-toughness and strong, deliver a tighter fit and less cam-out plating surface treatment, super anti-rust, long lasting and tips and arbitrary length, which helps to keep and bolts stuck to Can improve your work efficiency Fit for electric drills with speed regulating device, electric screwdrivers, hand screwdrivers.Please do not use drill bits on pneumatic tools, air dills, and the electric drill without speed regulation A long of the drill bit is reached due to its construction and technology Heat treated, durability, has high hardness, not easy to wear, Manufacturer: Yhplxyuus