With TIN coated tips in wolfram carbide. For drilling holes in tiles and other ceramic materials. Can also be used for wood, plastic, metal, tiles, aluminium and glass. Supplied in a practical wooden box.4, 5, 6, 8 and 10 mm. Drill bits 4 and 5 mm with 2-grooved drill tips, 6, 8 and 10 mm with 4-grooved drill tips.