Color Silver Material Diamond Quantity 1 Functions Great for grinding and polishing your nails. Features Diamond grinding needle made of high quality synthetic diamond raw materials meticulous precision reliable quality suitable for electric motorcycle machine engraving machine electrical machinery and equipment for assembly for ceramic metal plexiglass stone jade wood carbide and other super-hard materials of grinding drilling engraving miniature should be used with water cooling. Major head shapes: the cylindrical flat head round cylindrical spherical umbrella bullet a small piece of shaped pressed oval shaped inverted trapezoidal sharp-pointed needles etc. Packing List 30 x Needles