Features: Experience comprehensive air quality monitoring with our 9 in 1 Professional Indoor Air Quality Monitor, featuring realtime data visualization for PM2.5, PM10, CO2, temperature, humidity, formaldehyde, and TVOC level, ensuring a healthier environment. Equipped with a 2.8inch color TFT display and connectivities, this efficient device offers 60 day data storage and automatic time synchronization with your smartphone, making it both user friendly and efficient. Ideal for healthy family, including parent and seniors, as well as individuals with allergies, this monitor help prevent issue like drowsiness and allergic reactions by providing alerts to air quality changes. Perfect for use in offices, educational institutions, gyms, and commercial space, the device aids in maintaining great air conditions, enhancing concentration, comfort, and compliance with air quality standards. Instructions for use: 1. Press button for 3second to automatically turn on the device.2. Automatic counting after 60second of startup.3. Automatically switch display screen within 3seconds after startup.4. Press button three times in a row to lock current display screen, and then press it three more times to exit.5. A CO2 value greater than 1000.0 or a PM2.5 value greater than 100 will sound a alarm.6.Press button twice in a row to turn off the alarm sound. Specifications: Component:ABS Size:Approx.89x82x36mm/3.5x3.26x1.41inches Working voltages: 3.7V Current: 150mA Power: 0.6W Battery: 3.7V Battery capacity: 2000mAh Package Includes: 1Set 9 in 1 Professional Indoor Air Quality Monitor note: Please allow 1-2cm error due to manual measurement. Please make sure you do not mind before you bid. Due to the differences between different monitors, the picture may not reflect the actual color. Thanks!