Wireless Interconnected Smoke Alarm works on Photoelectric sensing technology to detect smoke particles entering the optical chamber using an infrared photoelectric sensor. Smoke alarms are built with dustproof, mothproof & anti– light interference design for functional reliability. Smoke alarm is powered for life by a 3V, 2 x CR123Alithium battery, this ensures that the battery will never require changing through its intended working life. Smoke alarm features Hush function to facilitate frequent testing of the alarm.