High-quality: carbide-tipped alloy head material with stronger hardness. Carbide drill bits are built to last and stay much longer than conventional steel drill bits. [U Type Slotted Design]U type slot design with fast drilling dust removal, triangular handle design, stable operation. Wide range of applications: the pointed design of the strong tungsten carbide tip can easily penetrate different materials (porcelain ceramic tiles, glass, mirrors, plastic masonry and wood). If you use the drill to drill concrete, brick wall and other hard materials (glass, porcelain floor tiles, marble or ), please use water for lubrication. 7 different sizes: 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm. 3 flat shank, these drill bits for glass perfectly match different drilling tasks, high drilling accuracy. Rotating thread design, drilling and chip removal smoothly. [Premium Performance]Spear pointed design, this strong tungsten carbide drill is , easy to locate, drill stable, fast speed, does not break the limit, opens neatly, smooth. The 3-flat shaft ensures that you can hold it firmly without slipping and scratching, not damage the tile glaze. colour: black + silver Material: carbide Package Contents: 14 x drill bits(3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm) 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.