Multifunctional Air Quality MonitorThis 5 in 1 CO2 monitor can detect real-time accurate detect air of Carbon Dioxide(CO2), Formaldehyde(HCHO), Volatile Organic Compounds(TVOC), CO, AQI. CO detection range: 0-2400PPM. CO2 detection range: 0-5000PPM. HCHO detection range: 0-1.999mg/m. TVOC detection range: 0-12mg/m. Full-Color LED Screen DisplayWith 5.5 inch LED screen digital display design, this air quality monitor is super easy to read and shows clearly real time data. The battery displays three color states: green, orange, and red. Green indicates sufficient power. Orange indicates half of the battery. Red indicates insufficient power(Need charge it in time). Large Capacity Rechargeable BatteryThe air quality detector has a built-in large capacity rechargeable battery, standby up to 5hours. You can check the air quality from anywhere, or have the device continuously monitor at a specific location. It will always take care of you and your family health. Easy To OperateOnce turn on the air quality meter, it will automatically measure the surrounding air quality for you.The air quality detector has three easy operation buttons. ON-OFF: Long press 3 seconds turn on or off. ANEW: Long press 3 seconds to reset instrument calibration. RESET: Long press 3 seconds data to clear and new detection.