1mm 20pcs. 2mm 20 pcs. 3mm 20pcs.Diamond Drill Bits - 1/8 shankPractical - Suitable to be used with hand drills, flex shafts and dremels.Perfect Jewelry Design Necklaces Earrings, Pendants, Bracelets with Sea Shells, Beach Glass, RocksMake Clean Holes in Tiles, Marble, Rocks, Ceramic, Porcelain, GemstonesExperience needed, you may break few bits during practice. Use with water - do not run dry.The total length of 1.77 inchesPlastic box packaging, easy to carry and storeCan drill Beach Sea Glass, Sea Shells, Rocks, Marbles, etc.Colour: silverMaterial: diamondSize: 1mm, 2mm, 3mmPackage Contents:2 sets * 30 diamond grinding needles setATTENTION: DO NOT RUN DRYWet drilling only. These are delicate, very small diameter diamond drill bits. The diamond coating is very thin. Can not take any abuse.Start the hole at an angle. While holding the drill in hand, carefully move the drill around just enough to ream out the sides of the hole. Let the tool do the work.Only the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.