15 different sizes of diamond drill bits: 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 25 mm, 28 mm, 30 mm, 35 mm, 40 mm, 50 mm. Suitable for drilling glass, tiles, bottles, jars, ceramic tiles, fiberglass, porcelain stoneware, slate, and light granite (especially for glass and tiles). The hole saw opens smoothly, without choking, without broken edges, without shaking, the drilling speed is very high, and the chip evacuation is easy. Slow drilling speeds, low drilling pressure, and increased use of water lubrication will significantly extend the life of the bit. Simple operation: trace a circular path. Initially, drill slowly at a 45° angle (vertical drilling is not permitted!) after finding a fixed position, then slowly hold the machine and objects horizontally.