Description Features:Mini Air Quality Monitor: Can measure CO2, temperature(/) and humidity at the same time, very suitable for home and office. With backside hole, you can hang the air quality monitor on the wall.High Accuracy Sensor: Adopts infrared sensor to measure CO2, temperature and humidity, which is more accurate, more reliable and more durable than traditional electrochemical sensors.Automatic Alarm System: When the CO2 value exceeds 1500PPM, an alarm will be issued automatically, you will hear beep sound, which notify you to keep the indoor environment ventilated in time.Large Screen Display: Clear and easy to view, and designed with colorful indicator light to show CO2 levels(1-700PPM green, 70-1500PPM yellow, 1500-5000PPM red), suitable for using in bedroom, office, school, car, etc.Built-in Rechargeable Battery: Built-in 2400mAh large capacity lithium battery that can be recharged by provided USB charging cable, long working time and quick charging.Specifications:Color: BlackSensor: Infrared SensorDetection CO2: 400-5000ppmDetection Temperature: -10 to 40/ 14 to 104Humidity Range: 0%-99% RHPower supply: Built-in 2400mAh Lithium BatteryCharging: 5V 1A USBItem Size: 9.8 * 9 * 4cm/ 3.9 * 3.5 * 1.6inPacking List:1 * Air Quality Monitor1 * USB Charging Cable1 * Users Manual(English Chinese)