These Battery Crossover Cables are suited for series connections. Sold as a set of two (one positive and one negative end). Each cable has a 3/8 inch copper battery eyelet and is sealed with thick wall heat shrink. These 2 Gauge 16 Inch Battery Crossover Cables – Series are TPE (Class K flexible wire). TPEs are tough, flexible, weather and oil resistant and are double insulated braided wire. This cable is more flexible than your typical battery cable, making it perfect for installing crossover cables in battery boxes.