This detector is perfect to help you detect the HCHO/TVOC, making you know more about the surrounding air quality. Powered by 2 * AA batterys(not included), easy to operate and use.   Features: Perfect to help you detect the HCHO/TVOC, making you know more about the surrounding air quality.  Built-in 360 degree detector ports, high accuracy and high sensitivity.  The LCD screen with blue color backlight indicates the value clearly.  With three color indicator lights(green/yellow/red), different color light for different level alarm.  Lightweight and portable, easy to carry. Suitable for home, office, factory, car or outdoor use.  Powered by 2 * AA batterys(not included).  One-key operation, easy to use.   Specifications: Color: White;  Display: LCD Screen with Backlight;  Measurement Range: 0~3.888mg/m³;  Resolution: 0.001mg//m³;  Detecting Temperature: -10℃~45℃;  Storage Temperature: -20℃~50℃;  Working Voltage: 2.4~3.2V;  Sensor Type: Semiconductor;  Powered by: 2 * AA Batterys (Not Included);  Item Size: 190 * 24.5mm / 7.48 * 0.96in;  Package Size: 225 * 85 * 40mm / 8.86 * 3.35 * 1.57in;  Package Weight: 200g / 7.05ounce;   Package List: 1 * Detector