*High Accuracy CO2 MeterUses high-precision sensor design and builds in NDIR sensor. The carbon dioxide measurement range reaches 400PPM-5000PPM. As soon as the CO2 content exceeds the set value, an alarm is given and the air purifier or the window must be opened for ventilation *Humanized DesignThe indoor air quality monitor has three types of air quality alerts, namely, three-color LED indicator, graffiti emoji and audible alarm. You can know the current indoor carbon dioxide concentration at any time. You can adjust it to the brightness of the product using the button on the back. Even if you put it in the bedroom at night, it will not affect your sleep. *Fashionable AppearanceThe design is simple, compact and portable, and weighs only 145g. It can be easily put in your pocket when you are on a business trip. It is also suitable for living room, bedroom, baby room, conference room, library and other places. *3-in-1 CO2 MonitorMultifunctional detector, PTH-5 air volume monitor can test carbon dioxide, temperature, humidity, built-in 5V 2400mAh large capacity lithium battery, easy to charge with USB cable standby for 8 hours, If you need long time use, we recommend that you keep it connected to the power supply. *What You Get: PTH-5 CO2 sensor * 1; User Manual*1; USB data cable* 1. If you have any problems with the goods you received, please contact our support team as soon as possible. We will serve you wholeheartedly.