Track 4 Main pollutant: The four main factors of air quality including HCHO, TVOC, CO2, CO be accurate detect. Portable devices&chargeable battery: monitoring the pollution index or school or office. Especially the place where are baby, children and pregnancy women Measurement Results Display: Small and design makes it easy to carry. People can easily read all the real time readings Easy to operate: when you turn the monitor on, it shows all the pollution index in the screen and it alarm if the air is unsafe Natural Airflow Detection Technology: which are widely used in homes, offices, enterprises, governments, schools and cars, etc. Colour:Black Material:Plastic Size:68x70x40mm Package Contents: 1 * Air Monitoring 1 * USB cable 1 * English instruction manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.