All-dielectric self-supporting (ADSS) cable is a type of optical fiber cable that is strong enough to support itself between structures without using conductive metal elements. It is used by electrical utility companies as a communications medium, installed along existing overhead transmission lines and often sharing the same support structures as the electrical conductors. Using single-mode fibers and light wavelengths of either 1310 or 1530 nanometres, circuits up to 100 km long are possible without repeaters. A single cable can carry as many as 144 fibers.