Features 1、The cutting wheels can turn your rotary tool into high-speed cut-off saw and grinding machine. 2、Inner part adopts high hardness steel material, long working life and not easy to deform. 3、Cutting part are diamond coated material for extra strength and long life of blades. 4、Sharp and strong, suitable for cutting gemstones, glass, ceramics, porcelain, carbide, etc. 5、Mandrel diameter: 3.0mm; cutting discs diameter: 19/22/25mm(with holes), 16/18/20/22/25/30/40mm(without holes). Specification Features: The cutting wheels can turn your rotary tool into high-speed cut-off saw and grinding machine. Inner part adopts high hardness steel material, long working life and not easy to deform. Cutting part are diamond coated material for extra strength and long life of blades. Sharp and strong, suitable for cutting gemstones, glass, ceramics, porcelain, carbide, etc. Mandrel diameter: 3.0mm; cutting discs diameter: 19/22/25mm(with holes), 16/18/20/22/25/30/40mm(without holes). Specifications: Color: Silver Mandrel Diameter: 3.0mm Cutting Discs Diameter: 19/22/25mm(with holes), 16/18/20/22/25/30/40mm(without holes) Packing List: 10 * Cutting Discs 1 * Storage Box Package List 10 * Cutting Discs 1 * Storage Box