This is an upgraded version of 5-in-1, with better performance, standby time of more than 30 hours when fully , closer to user experience, each indicator has a color prompt bar, you can choose the screen-off mode when you sleep at night, the device is working normally, once to switch the temperature, twice to turn on and off the sound, three times to enter the calibration interface, and four times to enter the screen-off state ( once to light up the screen) Protect Your Every Breath: Since means a lot to every one, the 5-in-1 air quality monitor be your . It can accurately monitor CO2, TVOC, HCHO, humidity& temperature. You can monitor the environment at any time Warm Notice: Please notice that this air quality monitor is designed for indoor spaces, so please close the door & before testing. Or else the data may not be accurate. We recommend using the monitor and keeping it working for at least 60 minutes before reading the data, Manufacturer: Duanthry