PLUG-IN 3-IN-1 CO DETECTORPlug-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 years life span), it can detect CO range from 0~999PPM (5%), temperature range from 14~122/ -10~50 (3%), humidity range from 5~95%RH (5%RH). Data refresh in 2 seconds without delay, real-time monitoring of gas safety in the environment.3-STAGE AUDIBLE VISUAL ALARMThe plug-in carbon monoxide alarm presents a 3-stage icon indication based on the CO concentration in the air. 0~50PPM (Green=Safe), 51~200PPM (Yellow=Warning), 201~999PPM (Red=Dangerous) The CO alarm defaults to an audible alarm of 85dB when the CO concentration reaches 51PPM. Press the D button to turn the buzzer (audible alarm) on or off.EASY TO USEShort press the "O" button to start self-test, if the green indicator light flashes 3 times and 3 beeps are emitted, the device is normal; long press the "O" button to switch between temperature units / . Short press "D" button to turn on or off the buzzer. Short press "H" button to adjust the brightness of the screen: high - low - turn off the backlight (when the backlight is off, the green indicator light flashes once every 5 seconds, which means the device is working).WIDELY USED The plug-in 3-in-1 carbon monoxide monitor simply plugs into an outlet and starts working. Ideal for indoor use, homes, apartments, living rooms with fireplaces, wood-burning fireplaces, kitchens, bedrooms, children's rooms, guest rooms, cellars, garages and RVs. The small, portable, pocket size is also better suited for hotel stays and domestic or international travel.EASY TO INSTALL & READThe CO detector is a plug-and-play plug-in design, which is suitable for any standard outlet with a voltage of 110-220V. The sleek and compact design makes it easy to integrate into your home.The 2.1-inch colorful screen displays carbon monoxide, temperature and humidity for easy reading. At night, you can also make the screen light up or turn off for easy viewing.