These points are covered with diamond particles for durability and strength making them ideal for use on hard materials The diamond-covered bits are ideal for fine precision engraving, carving, grinding and etching in glass, metal, plastic, rubber, ceramic, porcelain, leather and more With these multi purpose accessories your rotary tool functions as engraver pen and detail grinder Recommended maximum speed: RPM of 25.000 Fits with all Dremel Multi-/Rotary tools or other 3,2mm shank size multi- / rotary tools, Weight: 0.0220462262 pounds, Manufacturer: Dremel