ELECTRICAL, ELECTRONIC, ELECTRO-OPTICAL AND OPTICAL INSTALLATIONS, APPARATUS AND INSTRUMENTS; MONITORING (OTHER THAN FOR MEDICAL OR SURGICAL PURPOSES), RADIO, TELEVISION, ELECTRICAL CONTROL TESTING (OTHER THAN FOR IN VIVO TESTING), SIGNALLING, CHECKING (SUPERVISION), RADIOPAGING, RADIO-TELEPHONE AND RADIO TELECOMMUNICATION TELEPHONES INCLUDING PAY PHONES TELECOMMUNICATIONS AND TEACHING APPARATUS AND INSTRUMENTS; APPARATUS FOR INPUT, OUTPUT, RECORDING, TRANSMISSION OR REPRODUCTION OF SOUND OR ...