This product is a carbon dioxide tester, which can monitor the concentration of CO2 in the air, temperature, humidity and indoor formaldehyde and other harmful gases. No calibration is required, it can be tested when it is turned on, and it can accurately detect carbon dioxide. Features: 1. 5-in-1 function: The air quality detector is small and portable, and can accurately measure CO2 concentration, TVOC, HCHO, temperature and humidity. 2. Air convection design: Convective air is formed by openings on both sides and back of the detector, and real-time convection detection is more accurate. 3. 6.5-inch LED screen: 6.5-inch large screen displays power, time, date, CO2 value, TVOC, HCHO, temperature, humidity. Different font colors show different air quality. ( 400-800ppm: green means normal, 800-1800ppm: yellow means slightly higher concentration, more than 1800ppm: red means ultra-high concentration ) 4. Semiconductor sensor: It adopts semiconductor TVOC sensor, which has good precision, stable performance, strong anti-interference ability, low consumption and long service life. 5. Applicable occasions: The air detector is mainly used in living rooms, schools, hospitals, gyms, cinemas, offices, breeding greenhouses and other places. Note: 1. This product contains built-in lithium battery, please use standard DC-5V charger. 2. Do not block the air inlet and outlet during operation to avoid numerical deviation. 3. Do not use in a dusty environment with poor air quality so as to prolong the service life. 4. Do not use near high temperature, high humidity, dirty environment or strong magnetic fields to avoid inaccurate results or circuit failure. 5. Due to manual measurement, there will be a 1-2 mm error in the size. Thanks for your understanding. 6. Due to different light conditions and different monitors, item color displayed in photos may be showing slightly different from real object. Specifications: Color: White / Black ( Optional ) Sensor: Semiconductor Material: ABS + Electronic Components Screen: 6.5 inch LCD Screen Resolution: 240*240 CO2 Measurement Range: 400-5000PPM 400-800PPM ( Healthy ) 800-1800PPM ( Worse ) 1800-5000PPM ( Serious ) CO2 Measurement Sensitivity: 1PPM CO2 Measurement Concentration Error Value: 50PPM HCHO Measuring Range: 0.005-2mg/m TVOC Measurement Range: 0.008-2mg/m Temperature Measurement Range: 1~70 Temperature Measurement Accuracy: 1 Humidity Measurement Range: 0-99.9%RH Humidity Measurement Accuracy: 2%RH Charging Method: USB-Type C DC 5V/1A Battery Capacity: 3.7V 1200mAh Lithium Battery Item Size: 16*9*4.1cm / 6.30*3.54*1.61in ( L*W*H ) Packing Size: 18.5*11.5*4.8cm / 7.28*4.53*1.89in ( L*W*H ) Net Weight: 201g / 7.09oz Gross Weight: 380g / 13.40oz Package List: 1 * Tester ( Built-in Lithium Battery ) 1 * USB Charging Cable 1 * Instruction Manual ( English + Japanese + Spanish )