slice box cutter blades are compatible with slice Box Cutters, Pen Cutters and the slice Mini Cutter. These 100% zirconium oxide blades retain their edge much longer and feature our proprietary finger-friendly edge. These ceramic blades require no oil coating or special maintenance. They are non-sparking, non-magnetic and do not rust. When you need a fresh edge, simply reverse the double-sided blade. slice donates 1% of sales to Autism research related charities.