1. Five-in-one function: The multi-functional air quality monitor has a wide range of practical applications and can be used in places such as offices, classrooms, hotels, gyms, greenhouses, and warehouses to protect the living environment. 2. Carbon dioxide tester: It uses semiconductor sensors and air convection detection technology to detect the carbon dioxide concentration in the living environment relatively quickly and accurately. 3. LCD color screen: It can display carbon dioxide, formaldehyde (HCHO), total volatile organic compounds (TVOC), temperature, humidity, and battery level. The design of the LCD digital color screen allows users to read the data relatively easily and clearly even in a dim environment. 4. 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 exceeds 1500 PPM, the buzzer may sound an alarm. 5. Rechargeable design: It is equipped with a built-in 1200mAh rechargeable lithium battery with certain endurance. It comes with a Type - C USB interface and can be charged relatively quickly through a power adapter, mobile power bank, laptop, etc. 6. Color: Black 7. Material: Plastic 8. Package contents: - 1 air quality monitor Only the above package contents are included, and usually no other products are included. 9. Precautions: Light reflection and different monitors may cause the color of the item to vary slightly from the actual product. The allowable measurement error is around ±1 - 3 cm.