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. Rounded edge with safer rounded tip is 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!