17 Pcs Shank Grinding Head Diamond Grinding Head Mounted Bur Point Abrasive Tools K Needle for Rotary Tools shank diameter: 1/8'' 3 pcs, 3/32'' 14 pcs Medium grit for Carving, Grinding, Sanding, Etching and more... Works great on all natural materials Ceramics, Tile, Glass, Bone and Wood Great for Etching and more Long lasting when coolant is used