If you're going to jumpstart your car, do it with 100% copper. When it comes to jumping vehicles, copper is better than aluminum, and copper is what these are made of. Thick, 4-gauge, rubber-coated cables allow you to get to business without having to deal with tangles and knots, and they can be used in all weather conditions. Heavy-duty copper jaw clamps and a length of 20' make these Cables perfect for use on full-size trucks, vans, and SUVs. Heavy duty and 100% copper wiring...there's nothing more you need.