- 10 sizes (diameter): 4mm(4/25"), 6mm(1/4"), 8mm(5/16"), 10mm(3/8"), 12mm(1/2"), 15mm(3/5"), 16mm(5/8"), 18mm(11/16"), 20mm(3/4"), 22mm(7/8"), 30mm(1-1/5")
- rustless & durable: made of high strength carbon steel with smooth nickel plating surface to extend the service life.
- quick, sharp & smooth cut: coated with high quality diamond sharp, high precision and smooth cut with no broken edges fast
- suitable for drilling glass, tile bottles, blocks jars, fiberglass porcelain tile ceramic, slate mable, granite light stone
- not for use on concrete or for depths beyond about 1/2"
- attention: please keep the speed in 800-1000 per minute, keep adding water to keep the drill cool