This air quality detector uses an infrared sensor. The detection is very accurate and the quality is very good. Through Tuya linkage, it can give you a very good experience. Led display: carbon dioxide technology: infrared (NDIR) PM2.5 sensor technology: laser scattering Celsius Switch with Fahrenheit temperature unit Detection range: Carbon dioxide detection range: 400-5000 PM2.5 detection range: 0-999 μg/m detection range: 0-500 HCHO detection range: 0.001-1.999Mg/M3 TVOC detection range: 0.001-9.999 Mg/M3 Carbon dioxide alarm value: 1000ppm CO2 Alarm on/off function (if you don't like the alarm, you can turn it off manually) Power supply: 2000mah rechargeable lithium battery (included), including USB charging cable Dimensions: 190 x 52 x 80 mm Material: ABS Color: White Package contents: 1 detector 1 x USB cable 1 x English instruction manual Only the above package contents are included, other products are not included. NOTE: Light reflections and different monitors may cause the color of the item in the picture to differ slightly from the actual item. The measurement allowance is +/-1-3cm.