Item: BGTEC Vacuum Brazed Diamond drilling bits, Dry drilling for stone, masonry.... Quantity: 1/2/5pcs Specification: Hex Shank Quick-fit, available diameter 6mm, 8mm, 10mm, 12mm, 14mm, diamond length 10mm Application: For drilling granite & marble, masonry, concrete, tile/ceramic, glass, hard plastic..... Feature: 1. Wax inside for cooling, Dry drilling 2. Vacuum Brazed diamond technology provide very high efficiency, multi-purpose drilling 3. Long life drilling