This air quality detector with infrared sensor, detection is very accurate, the quality is very good through the Tuya linkage, can bring you a very good experience Led display: Carbon Dioxide Technology: Infrared (NDIR) PM2.5 sensor technology: laser scattering The unit of temperature between the Celcius and the Fahrenheit switch Detection range: Carbon dioxide detection range: 400-5000 ppm PM2.5 detection range: 0-999 micrograms/ meter detection range: 0-500 HCHO detection range: 0.001-1.999Mg/M3 TVOC detection range: 0.001-9.999Mg/M3 Carbon dioxide alarm value: 1000ppm CO2 alarm on/off function (if you don't like the alarm, you can manually turn it off) Power supply: 2000mah rechargeable lithium battery(included), including USB charging cable size: 190 x 52 x 80mm Material: ABS colour: White Package Contents: 1 x Detectors 1 x usb cable 1 x English instructions 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.