Perfect Connection & 15 Sizes- Glass core drill bit with 15 different sizes: 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 25mm, 28mm, 30mm, 35mm, 40mm, 50mm, perfectly suitable for your varied needs. High Quality & Sturdy Tile Drill Bit- Made of high-speed steel and therefore this tile drill bit has very good abrasion resistance and extreme hardness for a long service life. Precise & Smooth Hole- This glass drill bit set is very effective for drilling holes in bathroom wall tiles or mirrors and glass. It glides like butter over the tile with the fine edge of the drill bit and the hole is smooth and full without splinters. Never break chips again! Easy Installation & High Drilling Speed- Quick setup, perfect fit and also good chuck grip. With low resistance, these high-speed diamond drill bits are indispensable for assembly and disassembly in the private and professional areas. Wide Scope of Application- A must-have for the home improvement field and hobbyists! Suitable for DIY, profession, any hobbyist, DIY workshop, home use, home improvement enthusiasts, etc.