Triangle Drill Bit Set- It comes with 10pcs drill bits along 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 strong 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, ceramics, marble, brick walls and other hard and brittle materials. Special Design- The triangle drill bits with U-type housing design, for drilling remove dust quickly , without leaving any smudges. 3-flats shank drill bit allows easy grip and to be held firmly. Easy to use- Can be installed in most general electric hand drill and bench drill, all drill bits are placed at the storage box for a quick change.