4in1 SmokeCO detectorsCombination 4in1 detectors Integrated carbon monoxide, smoke, temperature and humidity sensors, real time to detector and show the environment gas safety for us. Plug in designCompatible with US 110V to 220V AC voltage Fits all US standard AC outlet in bedroom, kitchen, livingroom, basement, hotel room, etc. Builtin 2000 mAh backup batteryProvides 120h long working time, helps to cope with sudden power outages, and also can be used as a outdoor portable SmokeCO detectors. Equiped 2.1 HD Screen All the data real time show on the HD screen, we can read the data faster from the big icons like CO ppm, Smoke indicating bar, humidity, temperature, CO indicator icon, and alarm status. All gas environment safety we care Builtin UL standard independent Smoke sensor and CO sensor, HD screen visible and 85 dB audible design is real time detect the gas environment, bring you extra safety for you and family.