Universal for Drill Bits: This sharpener is driven by electric drill, universal to all drill bits, suitable for grinder power tools Corundum Grinding Wheel: The grinding wheel is made of corundum, which is wear resistant, rust proof, with high hardness, strong and durable, has long service life Simple Operation and Carrying: This sharpener is easy to operate and convenient to carry in your own toolbox, ideal for sharpening drill bits Money Saving: The sharpener sharpens the drill bit precisely and improves the usage rate of the drill bit, when the drill bit becomes dull, there is no necessary to buy a new one, which is time and money saving Self Centering Point: The corundum grinding wheel is self centering, no auxiliary center drilling or punching is required, convenient to use