Revolutionary ceramic replacement craft-blades fit most standard craft knife handles for a long-lasting, harder, sharper and safer tool. Safer than traditional metal blades, non-conductive, non-magnetic, chemically inert Zirconium Oxide never rusts and is the most durable material in the world, next to diamonds. 10x sharper and lasts 10x longer than metal blades. Oil-free finish is ideal for clean rooms. Fewer blade changes needed means fewer injuries, and lower costs – save money and your fingers!