Triangle Drill Bit Set - It comes with 10 drill bits and 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 is made of high quality cemented carbide, good abrasion resistance and extreme hardness. The carbide tip is durable and penetrates all different materials easily. Wide Application - High precision in center drilling, these porcelain drill bits are perfect for drilling holes in glass, tile, tiles, mirror, wood, ceramic, marble, brick walls and other hard and brittle materials. Special Design - The triangular drill bits with U-shaped housing design for drilling, remove dust quickly without leaving burrs. The drill bit with 3-face shank allows for easy gripping and firm hold. Easy to use - Can be installed in most common electric hand drills and bench drills, all drill bits are stored in the storage box for quick change.