This Diamond Drill Bits is well made of high strength material with durable smooth processed for practical use. It removes a from glass, tiles, marble, granite, ceramic or other. With 15 different size, it can be used with a standard electric drill. Perfect for both professional and personal use. Feature - ColorSilver - Material: Alloy. - Size: Approx. 5.5x5x5cm. - Made of premium alloy for durable and practical use. - Different sizes meets your requirement: Total 15 different sizes 6/8/10/12/14/16/18/20/22/25/28/30/22/30/35/40/50mm. - and , performance and cutting strength. - Suitable for Stone, Tiles, Ceramics, Glass and Granite, etc processing. - Attention: Please keep the in 800-1000 per minute, keep adding water to keep the drill cool, strictly prohibit from dry drilling! Package list: 1 x set of 15pcs Diamond Drill Bits Glass and Tile Hollow Core Drill Bits Extractor Remover Tools Hole for Glass Ceramics Porcelain Ceramic Tile