High Precision Carbon Dioxide MeterUsing high precision sensor design, built-in NDIR sensor. The carbon dioxide measurement range reaches 400PPM-5000PPM. Once the CO2 level exceeds the set value, the light change reminds you to trigger, you need to turn on the air purifier or the window for ventilation Humanized design The quality monitor indoor air has two types of air quality alarms, namely tricolor LED light and graffiti emoji. The current concentration of carbon dioxide in the indoor environment can be known at any time. You can use the buttons on the back to adjust the brightness of the product. Even if placed in the bedroom at night, it will not affect sleep. Fashionable AppearanceSimple, compact and portable design, weighs only 145 grams. It can be easily put in your pocket when traveling. Also suitable for living room, bedroom, baby room, conference room, library and other places. 3 in 1 CO2 MonitorMulti-functional detector, CO2 monitor air volume PTH-5 can detect carbon dioxide, temperature, humidity, built-in 5V 2400mAh large capacity lithium battery, easy to charge with USB cable. The PTH-5 CO2 monitor can work continuously for eight hours when fully charged. If you need to use it for a long time, it is recommended to keep it connected to the power supply.