Radon detectors; Pulse generators in the nature of electronic circuits; Carbon monoxide detectors; Safety sensors, namely, carbon monoxide detectors, smoke detectors, and combination carbon monoxide and smoke detectors; Gas sensors for measuring gas concentration; Device for testing the function and effectiveness of smoke detectors, carbon monoxide detectors and heat detectors featuring an aerosol spray; Combustible gas concentration detectors; Smoke alarms; Atmospheric oxygen monitors; Fire ...