Utility blade is made with 100 percent zirconium oxide, an advanced ceramic material, to provide a number of useful features that set it apart from typical steel blades. Zirconium oxide is nonsparking, nonconductive, nonmagnetic, chemically inert & never rusts. It is safe up to 1600 degrees Celsius. Slow-to-dull blade starts at an effective sharpness & retains its safe cutting edge for up to 11 times longer than steel for consistently smooth cuts again & again. Its natural edge retention utilizes a finger-friendly grind to resist piercing skin while maintaining its high-quality cutting performance. Plus, its safer edge eliminates the need for special sharps disposal boxes. Reversible blade with round tip is designed for use with the Slice manual utility knife, smart-retracting utility knife, auto-retractable utility knife, & manual carton cutter (each sold separately).