Specification: Hole dirll size: 5/6/8/10/12/14/16mm Material: Diamond Shank: Round Shank Diamond Length: 5/16'' (8mm) With cooling wax Application: For drilling granite,marble, masonry, concrete, tile,ceramic, glass, hard plastic..... Feature: Wax inside for cooling, Dry drilling without water. Very high efficiency, multi-purpose drilling. Long life drilling. Package Included: 1 x Drill Bit