Apparatus for recording, transmission or reproduction of sound or images, magnetic data carriers, recording discs, automatic vending machines and mechanisms for coin-operated apparatus, cash registers, calculating machines, data processing equipment and computers, accounting machines, amplifiers, antennas, audiovisual teaching apparatus, electronic balancing apparatus, camcorders, cassette players, compact disc players, counters, facsimile machines, games adapted for use with television receivers, headphones, intercommunication apparatus, invoicing machines, loudspeakers, measuring instruments, megaphones, microphones, money counting and sorting machines, electronic notice boards, pocket calculators, portable telephones, projection apparatus, projection screens, radios, vehicle radios, audio and video receivers, record players, remote control apparatus, scales, sound recording apparatus, stereos, tape recorders, televisions, television apparatus, electronic transistors, video recorders and players.;