Plug-in 3-in-1 Carbon Monoxide DetectorThe plug-in 3-in-1 Carbon Monoxide Detector can monitor carbon monoxide, temperature and humidity in the current environment in real time. Equipped with advanced high-reliability electrochemical sensor (5-year service life), it can detect CO in the range of 0~999PPM (5%), temperature range of 14~122/ -10~50 (3%), and humidity range of 5~95%RH (5%RH). Data is refreshed within 2 seconds without delay, real-time monitoring of gas safety in the environment. Three-level sound and light alarmThe plug-in carbon monoxide alarm displays a three-level icon indication according to the CO concentration in the air. 0~50PPM (green = safe), 51~200PPM (yellow = warning), 201~999PPM (red = dangerous) When the CO concentration reaches 51PPM, the CO alarm defaults to an 85dB sound alarm. Press the "D" button to turn the buzzer (sound alarm) on or off. Easy to Install and ReadThe CO detector adopts a plug-and-play design and is suitable for any standard socket with a voltage of 110-220V. The stylish and compact design makes it easy to integrate into your home. The 2.1-inch color screen displays carbon monoxide, temperature and humidity for easy reading. At night, you can also let the screen light up or turn off for easy viewing. Easy to UseShort press the "O" button to start self-test. If the green indicator light flashes 3 times and 3 beeps sound, the device is normal; long press the "O" key to switch between temperature units /. Short press the "D" key to turn the buzzer on or off. Short press the "H" key to adjust the screen brightness: high-low-off backlight (when the backlight is off, the green indicator light flashes every 5 seconds, indicating that the device is working). Widely UseThis plug-in 3-in-1 carbon monoxide monitor can start working by simply plugging it into the socket. It is ideal for indoor use, including homes, apartments, living rooms with fireplaces, wood-burning fireplaces, kitchens, bedrooms, children's rooms, guest rooms, basements, garages and RVs. The compact and portable pocket size is also more suitable for hotel stays and domestic or international travel.