The Dremel Diamond Point Cutting Wheel 22.2mm (545) is completely coated with fine diamond particles for working with hard materials, such as marble, concrete, brick, porcelain, ceramics, hard epoxy and soft and hard wood. Do not use with metal. The diamond coating adds durability and longevity, while producing smooth & fine cuts during cutting, sawing, carving and sharpening applications. The holes in the face of the Dremel Diamond Point Cutting Wheel 22.2mm (545) keep it cool during use, ensuring the Diamond Point Cutting Wheel will not lose its shape or break. The Dremel Diamond Point Cutting Wheel 22.2mm (545) contains one accessory in a pack, in addition to the Dremel Mandrel (402).