This indoor air quality monitor provides accurate results for many air quality measurements, including Carbon Dioxide(CO2), Formaldehyde(HCHO), Volatile Compounds(TVOC), Temperature and Humidity. The temperature unit of the home air quality tester supports conversion between Celsius and Fahrenheit, and there is a MAX button for viewing the maximum data in the current test record. The air quality detector is responsive, the detected data is displayed on a screen, and then the system evaluates the risk level (GOOD or OK or POOR), and when the value exceeds the normal range, the buzzer sounds quickly. Mute button: Turn on or turn off the alarm sound. In silent mode, the mute is not displayed and there is no alarm sound. The alarm sound is turned on by default. The carbon dioxide detector have a built-in 1000mAh rechargeable lithium battery, with a USB cable. When the battery is fully , the formaldehyde detector can last for 6-7 hours. When the battery power is too low, the battery will flash to remind the to charge, while charging, the characters in the battery will flash in sequence until the battery is fully displayed when the battery is fully . The indoor air quality monitor adopt an updated digital temperature and humidity sensor, and the high-precision sensor identifies and captures different pollutants in the mixed to the accuracy of the measurement of various indicators. The air quality analyzer help monitor air quality and is widely used in the home, office, car, kitchen, bedroom, gym, hotel, camping, party and more. color:As shown :ABS Package Contents: 1 x Air Quality Monitor 1 x USB cable 1 x English manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.