Safety apparatus and instruments in this class including voltage sensitive smoke, heat, or gas detection apparatus; fire prevention monitoring apparatus; switching apparatus; smoke detectors and smoke alarms, carbon monoxide detectors, leak detector systems; electric checking (supervision) and signalling systems for fire and smoke; alarm devices including medical alert alarms, assistance alarms, personal alarms for domestic and commercial use, electric and electronic locks and locking system, fire extinguishers, fire extinguishing systems, gas detection systems, flame detectors, heat detectors, heat alarms and intruder alarms / detectors emergency warning devices including bells, sirens and other sounding apparatus, visual indicating equipment, and intercommunication equipment including amplifiers and speakers of cone, horn and convoluted horn type; detectors; ultra violet electromagnetic radiation detectors (UV detectors), infared electromagnetic radiation detectors (IR detectors), passive infared detectors (PIR detectors), beam detectors and gas detectors; parts and fittings in this class for all the foregoing