Electrical apparatus for transmitting and receiving data, namely, switches, telephone, data, signal and information exchanges, multiplexors, optical multiplexors, connectors, digital cross connectors, asynchronous transfer mode switches, private branch exchangers, converters, modems, relays, repeaters, amplifiers, limiters, routers, transmitters, receivers, antennas, battery cables, coaxial cables, computer cables, electrical cables, ethernet cables, fiber optic cables, jumper cables, microph...