Air Cooled Cables are also known as Dry Jumpers, as they ‘jump’ when current passes through. While these jumpers usually have a cover, they are dependent on air to dissipate heat. Jumpers are made from large-diameter copper wire twisted into ropes with a terminal on each end. The length of a jumper is measured from the center hole of one terminal to the center hole of the other terminal. The terminals are available in a variety of configurations.