This is a multifunctional home air quality detector, mainly used to monitor PM2.5, HCHO, TVOC, CO and CO2 concentrations in air, and temperature and humidity. The instrument is equipped with a 3.2-inch color LCD display and a voice alarm prompt. Features: Four sensors, more professional, faster and more accurate. Real time data monitoring. Large LCD display, convenient for your reading anytime. Suitable for using in the office, living room, house with new furniture and decoration, kitchen, bedroom, classroom, etc. All data are displayed at the same time, and there is no need to switch the screen. Specifications: Color: white Screen size: 3.2in Resolution: 320 * 240 Working temperature: 0-50 Working humidity: 90RH Measurement range: HCHO: 0-1.999mg/m3 TVOC: 0-9.999mg/m3 PM2.5: 0-999ug/m3 Standard value: HCHO: 0.1mg/m3 TVOC: 0.6mg/m3 PM2.5: 35ug/m3 is perfect, 35-115ug/m3 is fine, 115-150ug/m3 is mediate, 150ug/m3 is bad Battery: 3.7V, 1500mAh Item size: 172 * 82 * 31mm / 6.8 * 3.2 * 1.2in Package size: 240 * 150 * 45mm / 9.4 * 5.9 * 1.8in Package weight: 520g / 1.1lb Packing List: 1 * Air Quality Tester