[ Fire alarms; gas leak alarms all for use as a component of a fire alarm system for detecting and warning of the presence of gas, used in the field of fire and harmful gas emergency prevention and detection; anti-theft warning apparatus, namely, theft alarms not for use with vehicles; heat detectors, ] smoke detectors [, flame detectors ] [ and gas detectors ] all for use as a component of a fire alarm system for detecting the presence of gas, used in the field of fire and harmful gas emerge...