... Product Description:* AC220V + 9V back-up Battery* Gas and Co Sensor* Hush and test Button* Visual and audible alarm ... monitor automatically.Specification:* Power supply: AC220V/50~60Hz* Sensor: Electrochemistry Co and Gas* Static current: ≤40MA* Alarm current: ≤80MA* Static ... control exhaust fan, electrical magnetic valve signal. Gas and Co Combined detector, Gas and Co Sensor with self test function