electrical warning installations and status sensors; photoelectric and infrared barriers, ultrasonic and vibrational emitters and receivers, electrical signal exchanges, [ fire alarms, ] burglar alarms, alarm and signalling units; [ combustion gas, gas, smoke, aerosol, flame and temperature detectors ]; detectors, sensors, electronic control panels and signalling apparatus for protection against burglary, break-in and assault; detectors, [ sensors and electronic control panels for access cont...