High Precision CO2 MeterUses high precision sensor design and integrates NDIR sensor. The carbon dioxide measurement range reaches 400PPM-5000PPM. As soon as the CO2 content exceeds the set value, an alarm is triggered and the air purifier or window must be opened for ventilation Humanized DesignThe indoor air quality monitor has three kinds of air quality alerts, namely three-color LED indicator, emoji graffiti and sound 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 MonitorMulti-functional detector, PTH-5 air volume monitor can test carbon dioxide, temperature, humidity, built-in 5V 2400mAh large capacity lithium battery, easy to be charged with a USB cable. What you get: PTH-5 CO2 sensor*1; User Manual*1; USB data cable* 1.