Ceramic box cutter blade. Blade stays sharp 10 times longer than steel. Blade is non-conductive, anti-magnetic, never rusts, and is chemically inert. Double-sided, hand-sharpened ceramic blade designed to reduce injuries by incorporating safer rounded tips. 1 double-sided ceramic blade is equivalent to 20 steel blades. Use only with Slice ceramic cutters. 4 dual-sided, rounded tip ceramic blades per pack.