Premium Quality: Our glass hole saw with positioning pilot drill bit is made of high quality diamond material, solid hardened steel body, and the surface is designed with nickel-plated coating, ensuring its high hardness, anti-rust, anti-corrosion, sturdy and durable. Precise Positioning Pilot Design: Each tile hole saw is designed with a removable positioning pilot drill bit, and the cutting head of the pilot drill bit is also designed with diamond coating, which makes it sharper and more durable, and effectively fixes the drilling position of the hole saw to cut holes quickly. Sharp and Clean Holes: These diamond drill bits with thicker diamond coating make the groove edge sharper, can cut precise flat-bottomed holes without chipping on smooth surfaces, such as ceramic tiles, ceramics, glass, marble, granite and terrazzo. (Cutting depth up to 30mm) Easy to Use: The operation is simple, without the need for other special guide tools. Use the tile hole saw installed with the