Perfect Connection & 15 Sizes: -15 different sizes of hollow glass drill bits: 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 25 mm, 28mm, 30mm, 35mm, 40mm, 50mm, perfect for application Your various needs. Made of high-speed steel, this ceramic tile drill bit has very good resistance to corrosion. wear and hardness. high, and has a long service lifePrecise and smooth holes: glass is very suitable; for drilling holes in bathroom wall tiles or mirrors and glass. It's like butter on a tile, the bit edge is fine, the hole is smooth and solid, and there is no debris. The chip never broke againEasy installation, fast drilling speed: - Quick setting, perfect fit, good chuck grip. These diamond drill bits with high speed have low resistance and are indispensable for assembly and disassembly in private and professional areas. Habitat and Hobbyist Improvement Suitable for DIY, professional, any hobbyist, DIY workshop, home use, home improvement enthusiasts, etc.