Features: brand new and high quality Diamond grinding for head is processes each kind of mold, hard alloy, glass apparatus, for ideal correction tools such as jade carvings. How to use: installed in the electric mill, engraving machine, hanging mill, gong machine hand drill drill drill and so on. Stone carving factory for stone carving lettering, carving, carved grinding, hollow and jade carving, carved ceramics, brick. Suitable for engraving pens, hanging mills, air mills, tools and other tools. Use with water as a lubricant. Used for mould grinding, grinding inner hole, suitable for electric grinder, carving machine, electric machinery supporting assembly, mainly used for carving glass, jade, fixed abrasive and hard objects. Specifications: Color:Silver Material:Diamond Shank Diameter: approx. 2.35mm/3mm (0.09/0.11 in) Total Length: approx. 40-45mm(1.57-1.77 in) for Head Diameter:1/1.5/2/2.5/3/4mm (0.04/0.06/0.08/0.1/0.12/0.15 in) Package Includes: 6x Diamond Coated Grinding Needle (1/1.5/2/2.5/3/4mm each 1pc) note: Please note that the photo does not show the actual size. Please refer to the detailed description. Due to the color calibration of each monitor, the color may be slightly different.