Good workmanship,reliable quality,suitable for hanging mill, electric mill, engraving machines, electric machineryand supporting assembly.Mainly used to polish glass, jade, repair abrasive and other hard objects.Electroplated diamond grinding, it is a deal correction tool forFit for:Grinding, engraving, cutting lines, polished, hollow, jade carving, glass engraving,etc.Color: SliverMaterial: Diamond+metalSize: shank diameter about 3mm, grinding diameter about 6mm,Total length about 45mmPackage Contents:20pcs grinding drill bitsOnly 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.