Self-Retracting Plastic Safety Box Cutter With 6 Blades Reduces accidents, down time and compensation rates. Rounded point blades reduce the possibility of puncture injuries. Safety spring slider pulls the blade into the knife body automatically. Minimum blade exposure. One button EZ opening - no screwdriver needed. For deeper cutting, remove blade, lift slider and snap off tab. For left hand operation, push button on back. Includes 6 blades. 12 knives per box.