This prop is used to simulate an incision. This real 6" metal utility knife as been specially rigged to emit stage blood from the blade. The actual blade has been removed and replaced with a plastic blade replica. There is a blood bulb mechanism attached to one side of the knife that allows the user to dispense blood from the end of the blade. Comes with two blood bulbs, the prop knife gag and a sample vial of stage blood. For professional use only. 6" long.