Meet whatever you require: the package includes 2 sets of drill bits in 2 different drill bit shapes, 1/4 inch, 5/16 inch, 3/8 inch, 1/2 inch There are 4 sizes of concrete drill bits different drill bits which will help you drill starting from the smallest drill bit and continuing to the required size.Durable material: The cobalt drill bit is made of quality cement carbide and the surface is anti-rust treated, which has a good abrasion resistance and extreme hardness, giving you a long service life.Sharp-tip design: This solid tungsten carbide tipped drill bit adopts sharp-tip design, fast speed, never not breaking the border, opening cleanly, which is easy to locate and drill stably And the 3-flat shank ensures that you can hold it firmly, no slipping or scratching, won't damage the tile enamel.Wide range of uses: the cobalt drill bit set is suitable for precise drilling of holes on the worm re, tiles, ceramics, wood, marble, brick walls and other hard and brittle materials This glass and tile drill bit has a fine drilling edge, and the hole is smooth and complete, without leaving any burrs.Easy chip removal: The w-type slot design provides low resistance, allowing for faster, smoother drilling and easier chip removal.