Link Knife is a simply designed aerotow or static tow release that can be used as a primary or backup. It consists of a plastic cylinder with a slot which is cut lengthwise. At one end of the slot, a blade is mounted. Typically, the weak link is passed through the slot, and held away from the razor with a rubber O ring. When a release is desired, a cord attached to the cylinder is pulled, overpowering the O ring and pulling the blade against the weak link.