Triangle Drill Bit Set - It comes with 10 pieces drill bits with two small boxes, easy to carry and organize. Includes 4 different sizes (4 x 6mm, 2 x 8mm, 2 x 10mm, 2 x 12mm), enough to meet your different needs. Durable & Sturdy - Our tungsten drill bit made of high quality hard metal, good abrasion resistance and extreme hardness. The carbide tip is durable and easily penetrates all different materials. Wide Application - High precision for centering drilling, these porcelain drill bits are perfect for drilling holes in glass, tiles, tiles, mirror, wood, ceramic, marble, brick walls and other hard and brittle materials. Special Design - The triangle drill bits with U-type housing design, for drilling dust quickly, without leaving burrs. 3-flats drill bit shank allows easy grip and to be held firmly. Easy Use - Can be installed In most general electric hand drills and bench drills, all drill bits are placed in the storage box for quick change.