Multiple Detectable Gases: For everyone it is necessary to know the air quality of where you live. Enhanced indoor air quality monitor integrated with DART electrochemical sensors capable of accurately detecting the air of Carbon Dioxide (CO2), Formaldehyde (HCHO), Volatile Organic Compound (TVOC). These readings involve the detection of Toluene, of harmful chemicals and pollutants in the air such as carbon dioxide. DIGITAL HD LED SCREEN DISPLAY: After turning on and preheating the air detector for two minutes, the LED screen clearly displays real-time CO, CO2, HCHO, TVOC, AQI of five indicators. The display battery shows three color states: green, orange, and red. Green indicates sufficient power. Orange indicates half battery. Red indicates insufficient power (please charge it in time). EASY TO USE: The air quality detector has three easy operation buttons. ON-OFF: long press 3 seconds to turn on or off. AGAIN: Long press 3 seconds to reset instrument calibration. RESET: long press 3seconds data to clear and new detection. PORTABLE: This air quality meter is compact and very easy to carry, size: 4.8*2.5*1.1 inch. The bottom angle of the instrument is 15 degrees. This air quality tester is ideal for living room, bedrooms, cars, offices, school and other indoor occasions. Especially places with babies, children, old people and pregnant women. Please note: Please note that this air quality monitor is for indoor place in the home, please close door and window before testing. We recommend that you use the monitor as a fixed unit and focus on long-term average values (at least 60 minutes) and the overall indication of environmental quality. So that the value is clearer and the value complete. will be displayed after 10 minutes of power on.