Features:  3 in 1 air quality monitor, accurately detect the level of CO2, Temperature and Humidity.  Adopted high precision infrared sensor and high-performance chip, providing fast and reliable detection.  Easy to check the real-time data on the colorful LED display with large digits, fast capturing the results.  4 flashing indicator levels demonstrate different CO2 concentration, the alarm will be given out when value exceeding 1000PPM.  Built-in 2000mAh large capacity lithium battery, get rid of cable annoyance, flexible to use and charge.  Palm size with lightweight, perfect for home, school, office, hotel, warehouse and other environments.    Specifications:  Material: ABS  Color: Black  Voltage: DC5V  Screen: Color LED Display  CO2 Detection Method: Infrared (NDIR)  CO2 Detector Range: 400-5000PPM  Real Time Reading: 1S  Alarm Sound: ＞1000PPM  CO2 Indicator:  0-999PPM: Green Light Flash  1000-1999PPM: Yellow Light Flash  2000-2999PPM: Orange Light Flash  3000-3999PPM: Red Light Flash  Above 4000PPM: 4 Lights Flash  Battery: 1 * 3.7V Lithium Battery  Item Size: 137 * 80 * 35mm / 5.4 * 3.1 * 1.4in  Item Weight: 165g / 5.8oz    Package List:  1 * Carbon Dioxide Detector  1 * USB Cable  1 * Manual