Martor Secunorm Mizar Safety Knife

With its 15mm cutting depth, this retractable knife can cut through tough materials such as three-ply cardboard with minimum effort. As a safety feature, the blade is only revealed when the lever is squeezed, and hidden as soon as it's released. A locking mechanism makes it possible to prevent the lever from being activated accidentally. Each blade has two cutting edges as well, making each last twice as long.