1、High Accuracy: This desktop air quality tester is highly accurate and measures CO2 levels. With a clear, easy to read display that shows CO2 levels from 400‑5000ppm, in addition to temperature and humidity, this monitor ensures that you breathe freshing air. 2、Real Time Monitoring: This CO2 air quality tester samples 1.5s/time, and the alarm equipped CO2 monitor alerts you with a siren when the PPM value increases (supports turning off the alarm). You can calibrate the CO2 monitor to ensure its accuracy over time. 3、2000mAh Large Capacity Battery: This air quality monitor has built in 2000mAh large capacity battery with usb interface charging port, you can use our CO2 monitor for a long time without replacing the battery frequently. Charging the CO2 monitor for 2 hours will ensure 24 hours of use. You can also adjust the brightness of the monitor to guard your eyes in different light. 4、Easy To Install: This CO2 temperature humidity tester is designed with a stabilizing bracket, which can be stably placed on the desktop stall, which can meet all your needs, and can be placed in a variety of places, which is easy to carry and use. 5、Wide Application: This CO2 temperature humidity detector has a wide range of applications and can be used for sleeping indoors, traveling, or on the go. It is great for use in the home, office, classroom and other spaces. Item Type: CO2 Detector Material: ABS Detection Range: 400-5000ppm Temperature Range: -10°C-50°C Humidity Range: 20%-85% RH Sampling Time: 1.5 Seconds Battery: 1 x 2000mah Rechargeable Lithium Battery (Included) 1 x Air Quality Monitor 1 x Manual 1 x USB Cable