Remote control apparatus, monitoring apparatus, electric; sound recording apparatus; sound transmitting apparatus; computer memory devices; camcorders; video cassettes; video telephones; video screens; detectors; dictating machines; floppy disks; sound recording discs; disks, magnetic; optical discs; locks, electric; bells (warning devices); signal bells, electric; interfaces for computers; identity cards, magnetic; encoded cards, magnetic; magnetic encoders; compact discs; compact discs (aud...