Features: - This is a brand new product - This diamond bit core drilling removes a complete circle glass, tiles, marble, granite, ceramic or other material and only needs water for lubrication - Can be used with a standard electric drill (not included) - Easy to use, high quality, good performance, long life - Excellent for making clean and accurate hole on glass, tile and marble - Always use lubricant (water), otherwise the diamond core drill will burn Description in details: Material: steel Good Performance and long life. Excellent for making clean and accurate hole on glass and tile. Works better with a electric drill (Excluding in the item). Total length: about 5.5cm Applicable Industry: Suitable for Stone, Tiles, Ceramics, Glass and Granite, etc Processing. Specifications: Model: 5 Pcs 6mm -- 14mm 6mm / 0.23 8mm / 0.31 10mm / 0.39 12mm / 0:47 14mm / 0:55 Package Includes: 5pcs * Diamond Coated Drill Bit