High-quality diamond-coated drill bits 4 different sizes-1mm, 1.5mm, 2mm, 2.5mm 5 pcs each Suitable for drills, flexible shafts and milling cutters. Jewelry designers used to drill holes in sea glass, shells, rocks, marbles, stones, etc. on the beach. Make your own earrings, pendants and bracelets. colour:Silver Material:Emery Package Contents: 20 x Diamond Coated Drill Bits Only the above package content, other products are not included. Note: Light reflection 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.