Features: The diamond coated core drill bit removes a complete circle from glass, tiles, marble, granite, ceramic, or other materials and only requires water for lubrication. Comes in multiple sizes for various applications. Compatible with a standard electric drill. Constructed from metal with diamond coating, offering high hardness, wear resistance, and durability. Easy to use: begin drilling at a slight angle to create a circular guide groove, then continue straight. Always use water as lubrication to prevent overheating and damage to the drill bit. Specification: Material: Metal with Diamond Coating Hole Sizes: 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 25mm, 26mm, 28mm, 30mm, 40mm, 50mm (equivalent to 0.23in to 1.97in) Quantity: 15 pieces Weight: Approximately 358g (12.6oz) Package Includes: 15 x Hole Saw Drill Bits Note: The updated and original versions of this product may be shipped randomly. Please accept this condition before placing your order.