UPTODATETOOLS -: Diamond Drill Bit Set, 4 PCS Glass Hole Saw for Tiles Glass Ceramic Marble Bottles DIY,35mm -- 50mm Features: Good performance:diamond dust coating offers superior performance and cutting strength. Wide application of the Tile Hole Saw: coated core drill bit removes a complete circle from glass, tiles, marble, granite, ceramic or other materials and only needs water for lubrication. 4 SIZES: No matter which size hole you want, it can always drill a perfect hole for you. Specifications: Material: high quality steel, diamond dust coating Color: Silver Size: 35 - 50mm ( 35mm,40mm,45mm, 50mm) Quantity: 4 pcs Note: If you smell burning, back off! Either your speed is too high or the pressure you're applying is too much. You're drill bit should never be hot to the touch, not even warm. ?Slowest speed ? Always use lubrication (water) ? Minimum pressure Package Included: 4 x Tile Hole Saw