This indoor air quality monitor provides accurate results for many air quality measurements, including Carbon Dioxide(CO2), Formaldehyde(HCHO), Volatile Organic 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 symbol is not displayed and there is no alarm sound. The alarm sound is turned on by default.The carbon dioxide detector have a builttoin 1000mAh rechargeable lithium battery, with a USB cable. When the battery is fully , the formaldehyde detector can last for 6to7 hours. When the battery power is too low, the battery frame will flash to remind the user to charge, while charging, the characters in the battery frame will flash in sequence until the battery symbol is fully displayed when the battery is fully .The indoor air quality monitor adopt an updated digital temperature and humidity sensor, and the hightoprecision sensor identifies and captures different pollutants in the mixed gas to the accuracy of the measurement of 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 shownMaterial:ABSPackage Contents:1 x Air Quality Monitor1 x USB cable1 x English manualOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1to3cm.