In the world of offshore fishing the Ripper would be used to cut the line to release a Marlin or any other sportfish. For the rest of us, it is a great tool to cut through most any fishing line (monofilament, fluorocarbon, or braid) that is tangled or after tying a knot or whatever. It is made from the same high pressure injection molded Nylon as the Bill Blade sheath. It has a #12 Surgical scalpel blade inserted in the hook or mouth so it is safe but very effective at cutting up to 300lb monofilament fishing line.