Dremel Diamond Wheel Point   Applications: For fine detail work, cutting, engraving, carving, touch-up and finishing. Use on wood, jade, ceramic, glass, hardened steel, semi-precious stones and other hard materials. Bits are covered with diamond particles   Technical specifications Shank diameter - 2.4 mm Working diameter - 4.4 mm Maximum speed - 25000 rpm Quantity - 1 Order number - 26157105JA