RCA

REMOTE CONTROL UNITS FOR RADIO AND TELEVISION RECEIVERS [ ; ELECTRONIC METAL DETECTORS USED IN CONNECTION WITH BELT CONVEYERS, FOR DETECTING THE PRESENCE OF UNDESIREABLE METAL OBJECTS PASSING THROUGH OR BY THE DETECTOR; ELECTRICAL MESSAGE SIGNALLING SYSTEM USED IN HOTELS; ELECTRONIC RAILROAD CAR DETECTION DEVICES DESIGNED TO DETECT THE PRESENCE OF MOVING OR STATIONARY CARS OR LOMOTIVES; RADIO OPERATED PUBLIC SAFETY ALARM SYSTEM UTILIZING AN EMERGENCY CALL BOX, BASE STATION COMPUTER DECODER AND VISUAL DISPLAY AND PRINTOUT UNITS ]