A. [Five-in-one function]: This multifunctional air quality monitor has diverse functions and wide applications. It can be used in places such as offices, classrooms, hotels, gyms, greenhouses, and warehouses. B. [LCD color screen]: It can display carbon dioxide (CO₂), formaldehyde (HCHO), total volatile organic compounds (TVOC), temperature, humidity, and battery level. The LCD color digital display allows for easy and clear data reading even in dark environments. C. [Carbon dioxide tester]: It uses a semiconductor sensor and detects through air convection, enabling quick and accurate detection of carbon dioxide concentration in the living environment. D. [Four-color indicator light and alarm buzzer]: When the carbon dioxide concentration is between 0 - 799 PPM, it shows green; between 800 - 1199 PPM, it shows yellow; between 1200 - 1599 PPM, it shows orange; and at 1600 PPM and above, it shows red. When the carbon dioxide concentration is higher than 1500 PPM, the buzzer will sound an alarm. E. [Rechargeable design]: It has a built-in 1200mAh rechargeable lithium battery with strong endurance. It is equipped with a USB Type-C interface and can be quickly charged via a power adapter, mobile power bank, laptop, etc. F. Screen: LCD digital color screen G. Voltage: 5V DC H. Detection principle: Semiconductor sensor I. Carbon dioxide detection range: 400 - 5000 PPM J. Carbon dioxide detection sensitivity: 1 PPM K. Formaldehyde detection range: 0 - 0.6mg/ L. Total volatile organic compounds detection range: 0 - 2.0mg/ M. Temperature measurement range: 0 - 50 N. Temperature measurement accuracy: 1 O. Humidity measurement range: 0~99%RH P. Humidity measurement accuracy: 2%RH Q. Charging port: Type-C, 500mA R. Built-in battery: 3.7V 1200mAh lithium battery S. Dimensions: 90x70x35mm T. Material: ABS U. Color: Black V. Packaging contents: - 1 air quality analyzer - 1 USB data cable - 1 English manual - Only the above packaging contents are included, and no other products are included. W. Precautions: Light and different displays may cause slight differences between the color of the item and the actual product. The measurement allowable error is +/- 1 - 3cm.