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