Diamond hole saw / core drill style bit. 10 sizes: 6mm, 8mm, 10mm, 14mm, 16mm, 18mm, 22mm, 35mm. 40mm, 50mm Usage: Drill glass, tile bottles, block jars, fiberglass porcelain tile ceramics, slate marble, granite light stone SPEED KILLS: Reduced drilling speeds, low drilling pressure and increased use of water lubrication will significantly extend drill bit life Warning: Not for use on concrete or for depths longer than approx. 1/2 \"; Sufficient water is a MUST HAVE for lubrication and cooling when drilling About shipping: All items will be shipped within 3 business days after payment is received. In most cases, you will receive them within 8-12 days then. The specific delivery time depends on the circumstances. If you have any questions, please feel free to contact us During the shopping process, if you have any questions, please feel free to contact us, we will reply you within 24 hours, wish you a happy shopping Thank you for your cooperation and we will make you feel satisfied.