High Quality Multi-purpose Drill Bit Set: Tungsten Carbide Tipped for prolonged life Special Design: U-type slot design for fast drilling dust removal, 3-flats allow drill bit to be held tightly and stably in drill. Cut Perfect Circular Holes: Suitable for glass, ceramic tile, wood, stone, concrete, brick, etc. When drilling hard materials (glass, porcelain floor tile, marble or granite), please use water for lubrication. Ideal for drilling fastener holes in bathroom tiles or wall mirrors. Once it drills through the tile or mirror, this drill bit will easily handle any masonry behind it. This product cannot be used for drilling tempered glass or pure concrete. When drilling, use only the flat drill function; do not use impact force. When drilling fragile items, keep drilling speed moderate and apply light pressure to avoid damaging the material. Color: Black + Silver Material: Tungsten Carbide Size: Blade diameter 6mm, 8mm, 10mm, 12mm Package Contents: 6pcs Ceramic Tile Drill Bits Note: Light and display differences may cause slight color variation between the image and the actual item. Measurement error allowed is +/- 1-3cm.