I love these Diamond Drill They come in a 10 pack I bought these for crafts for cutting bottles it add lights and other things these come in handy forsure but you could use they for all kinda stuff like cleaning and accurate hole on glass and tile.Use for Tiles, Glass, Fish Tanks, Marble, Granite, Ceramic they come in different sizes 6mm/8mm/10mm/12mm/15mm/16mm/18mm/20mm/22mm/30mm they are perfect for me I would highly recommend to my family and friends