Box cutter blades are compatible with Slice box cutters, pen knives & the Slice Mini Cutter. These 100 percent zirconium oxide blades retain their edge 11 times longer than steel & feature proprietary finger-friendly grind. Ceramic blades require no oil coating or special maintenance. They're nonsparking, nonmagnetic & never rust. Rounded tip offers extra protection against accidental puncture injuries. When you need a fresh edge, simply reverse the double-sided blade.