Cool Hand Zirconia Ceramic Utility Blade, Replacement Blades, Box Cutter, 6 Pcs per Pack 1. Zirconia ceramic: Never rusts, anti-static, non-magnetic, non-metallic, non-oil 2. Less blade changes means less injuries - reduces chance of injuries, lowers costs 3. Single blade is equivalent to-20 metal blades 4. Sharper and last longer than steel blades, Up to 10x sharper than steel 5. Good for fine cutting, exchangeable blade