240 volt Photoelectric Smoke alarm with 9v Battery back up

Model No: 3S 240-1 The unit is a photoelectric 220~240V AC, 9V DC battery back-up smoke alarm device. It is particularly sensitive for detecting visible micro-particles (associated with smoldering fires) and reacts faster than ionization alarms. An example of such smoldering fires is a cigarette burning in a couch or bedding a common cause of devastating blazes. Please note this device does not detect flames, heat, carbon monoxide or other hazardous gases. It has many advanced features and an extended operational life with the included battery.