Feature: 1. High Accuracy: This PM2.5 air quality tester meter is highly accurate and can measure PM2.5 levels. With a clear, easy to read display that shows PM2.5 levels from 0 to 999ug/m³, in addition to temperature and humidity, this monitor ensures that you breath well. 2. Real Time Monitoring: This air quality tester samples 1.5s/time, and the alarm equipped PM2.5 monitor alerts you with an audible alarm when the ug/m³ value increases (supports turning off the alarm). You can calibrate the PM2.5 monitor to ensure its accuracy over time. 3. Rechargeable Battery: This PM2.5 temperature humidity detector has a built in 1600mAh high capacity battery with usb interface charging port, you can use our PM2.5 monitor for a long time without replacing the battery frequently. 4. Easy To Install: This PM2.5 thermometer humidity monitor is designed with a stabilizing bracket, which can be stably placed on a desktop and other places, which can meet all your needs for indoor sleeping, traveling or on the go. 5. Compact And Lightweight: This air quality monitor is small, lightweight and easy to carry around, making it ideal for use in your home, office, classroom and other spaces. You can also adjust the brightness of the monitor to guard your eyes in different light. Specification: Item Type: Air Quality Tester Material: ABS PM2.5 Detection Range: 0-999ug/m³ Temperature Detection Range: -10°C-50°C Humidity Detection Range: 20%-85% RH Sampling Time: 1.5 Seconds Battery: 1 x 1600mAh Rechargeable Lithium Battery (Included). Package List: 1 x Air Quality Tester 1 x Manual 1 x USB Cable