NT's self-retracting safety knife in either the heavy duty model or the compact mini model. Each safety cutter has a spring activated safety mechanism which automatically slides the blade back into the holder with just a simple release of the slider. These retractable blade knives prevent blade from sticking out of holder when not in use to reduce chance of injuries at the workplace. NT's heavy duty self retracting knife has replaceable blades; short straight snap off blade and hook blade, and perfect to use in shipping and receiving department to cut straps, open cartons, etc. NT's handy mini utility knives are perfect for safely opening envelopes, removing tags, etc. NT also has a safety carton opener that is perfect for the warehouse for removing staples and cut packing tapes without damaging the contents. The blades used in these safety knives are made from either high quality carbon tool steel or stainless steel, and produced through multiple stages of precise process to obtain the ultimate sharpness and optimum edge-retention. Made in Japan.