72272337
May 25, 1967
Nov 12, 1968
ELECTRONIC AUDIO DETECTION SYSTEMS INDICATING AN ALARM CONDITION CONSISTING OF SOUND DETECTION MEANS, CANCELLATION SENSITIVITY CONTROLS, RESET CONTROLS, INPUT SENSORS, KEY SWITCH AND TIME CLOCK TAMPER SWITCHES, EMERGENCY BATTERY SOURCES, ALARM RELAYS, INPUT UNITS, AND PARTS THEREOF
Housewares and Glass