Compatibility: the diamond cut off wheels are compatible with the majority of rotary and air tools, electric grinder and : the diamond cut off discs are thin, completely coated with fine diamond particles, breathing holes for reducing heat and removing debris, great for making slots and slit Wide range of usage: This diamond cutting wheel are suitable for doing DIY, cutting, sawing, carving, sharpening and filing hard materials including all kinds of precious stones, jade, marble concrete, brick, porcelain, ceramics, epoxy and other hard woods, but not recommended for metal. Notice: For your safety, please must wear gloves and goggles and be care around spark when using mandrel diamond cutting tools. It may become very hot when cutting, so add some water to keep it cool. Disc diameter: 0.87 inch/ 22 mm Disc thickness: 0.02 inch/ 0.6mm Mandrel length: 1.50 inch/ 38 mm Mandrel diameter: 0.12 inch/ 3.0 mm colour:Silver Material:diamond Package Contents: 20 * Diamond cutting wheel 4 * Mandrel Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.