High Quality Multi-purpose Drill Bit Set: Tungsten Carbide Tipped for prolonged life Special Design: U type slot design with fast drilling dust remove, 3-flats shank allows drill bit to be held tightly and stably in power drill. Cut Perfect Circles Holes: Suitable for glass, ceramic tile, wood, ceramic, stone, concrete, brick, etc. When drilling hard material (glass, porcelain floor tile, marble or granite), please use water for lubrication,Perfect for drilling fastner holes in bathroom tiles, or wall mirrors. Once it drills through the tile or mirror this drill bit will cope easily with any masonry behind it Tbhis product cannot be used for drilling toughened glass and drilling of pure concrete ,When drilling, use only flat drill function, do not use any impact force ,When drilling fragile items, the drilling speed is not too high, the pressure should not be too large, so as not to damage the drilled items Color: black + silver Material: tungsten carbide Size: Blade diameter 6mm 8mm 10mm 12mm Package Contents: 6pcs * Ceramic Tile Drill Bits Only the above package content, other products are not included. Note: Light 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.