It looks like a gun and you hold it like a gun, it has a trigger too. This gun doesn't shoot though, it has a open string at the end of it. You put that string under the rib (rib cage has been sawed in two before) and then when you pull the trigger, it rapidly pulls on that string, or rather the metal it's attached too.
It's so stupid, you gotta use your other hand to hold that string in place, and press down on the bone as hard as you can, otherwise the string just pulls the entire thing and your hand on it, and you get a healthy strong knock on your knuckles as the pistol pulls it into itself. My friend gave up after he was employed in that part