The Slice Ceramic Safety Cutter is the most versatile tool you'll ever own. The Finger-Friendly¢ ceramic blade is harder than steel, stays sharp, never rusts and is a safe substitute for scissors or traditional safety knives. The Slice¢ Ceramic Safety Cutter is rated at 8.2 on the Mohs hardness scale (compared to metal knives, rated at 5.5). It is made from Zirconium Oxide, a non-porous, non-stick material that repels acid, salt and rust. It comes with a rubberized non-slip finish, built-in magnet and key ring hole and can be used to remove shrink-wrap and open plastic packaging among other materials.