With a shallow cutting depth of 9mm, this MARTOR safety knife is perfect for cutting through packaging without damaging the contents inside. The inbuilt safety lock and fully automatic retractable blade provide reliable protection against hand injuries, while the simple blade-changing mechanism makes it easy to use all four cutting edges of each blade by using a magnet to help keep it in place. Using a trigger to release the blade too, this safety knife is ergonomically designed to be Comfortable for prolonged use.