... .use broad 4.AC110-240V DC9V Battery Description:1.GAS detector,Smoke detector,CO Detector,Scarbon monoxide detector,sending wireless signal alarm independently.2.while ... for room,hall,kitchen,party,no smoking place,hotel,factory and so on. Instruction:Plug in the power, the green ... light, at the same time the product start to detector, when detect gas or smoke in air reach a certain density, began ...