Unique Cross Angle Design: Low cutting resistance, stable drilling characteristics, fast speed, and no broken edges. The opening is neat and smooth, with no broken edges, no shaking, and easy to peel off. 5 Different Sizes: Suitable for your different needs. It can be installed on general hand-held electric drills and bench drills. The clamping range of the machine drill is 10mm and above. WIDELY USED: Professional glass and tile drill bits provide smooth and precise drilling on tiles, marble, sheet metal, mirrors, and glass. Remember to add water or coolant when drilling. Size: 3+4+5+6+7 mm Note: The data are all manual measurements, please allow an error of 1-3cm, due to the difference in light and display, there will be a certain color difference, whichever is the actual object received. Delivery quantity: (as shown in the main picture)