Faithfull Grinding Wheel Assortment contains 36 grinding wheels of assorted sizes and grits with a 1/4in shank to suit most electrical and cordless drills. They are ideal for sharpening and grinding steel, and the pack contains six each of the following: Ø77 x 12mm Fine Ø50 x 12mm Fine Ø37 x 24mm Fine Ø65 x 6mm Coarse Ø50 x 6mm Fine Ø15 x 24mm Coarse SAFETY TIP Faithfull grinding wheels are for use in power or cordless drills only and are not suitable for use in die grinders or high-speed air tools.