Triangle Drill Bit Set - Includes 10 drill bits accompanied by two small boxes, easy to carry and organize. Includes 4 different sizes (4 x 6 mm, 2 x 8 mm, 2 x 10 mm, 2 x 12 mm), enough to meet your different needs. Durable and Sturdy - Our tungsten carbide drill bit is made of high-quality carbide, with 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 glass, tile, mirrors, wood, ceramic, marble, brick walls and other hard and brittle materials. Special Design - The triangular drill bits with U-shaped housing design for drilling quickly remove dust, leaving no burrs. The 3-point flat-shank drill bit provides an easy grip and a firm hold. Easy to use: Can be installed on most handheld and benchtop electric drills; all drill bits are stored in the storage box for quick replacement.