Size: Head diameter: 4mm or 0.15inch Shank diameter: 3mm or 0.11inch Length: 45mm or 1.77inchCylindrical tip, diamond-coated heads that can be mounted on electronic grinders, gantry grinders and hand drills.Used for engraving, trimming, precision grinding and internal grinding of carbides in ceramics, glass, precious stones, alloys and many other abrasive materials.Excellent for carving, engraving, forming, drilling and Smoothing the surface.Diamond coated drill bits are suitable for glass, tile, stone and hardened metals.Colour: SilverMaterial: DiamondPackage Contents:20 x Diamond Grinding BitOnly 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.