Diamond hole saw / core drill. 10 sizes: 6mm, 8mm, 10mm, 14mm, 16mm, 18mm, 22mm, 35mm. 40mm, 50mm Usage: Drilling 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 the life of the drill bit Warning: Not for use on concrete or for depths longer than approximately 1/2 \"; Sufficient water is a MUST 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 contact us During the shopping process, if you have any questions, please contact us, we will reply to you within 24 hours, wish you a happy shopping Thank you for your cooperation and we will make you satisfied.