Features:  PDF Data Export Function -- 2000 goups value records, display the MAX, MIN and AVG values of carbon dioxide, temperature and humidity.  Export PDF function allows you to connect with computer and export the PDF file for conveniently checking and analyzing.  4 Inch TFT Full Color Display -- Large screen real-time display current time, date, CO2(MAX, MIN and Grade), temperature, relative humidity, data record interval and recordings and battery power.  Display backlight brightness, standby time and RGB indicator light are adjustable.  Alarm Setting -- Real time CO2 monitoring by the high precision sensor, and it will alarm you once the CO2 is exceed the setting value. The buzzer alarm can turn off according to your demands.  2200mAh USB Rechargeable -- 2200mAh large battery capacity, 3 hours full charging and support over 10 hours working demands. USB charging port can be powered via almost any standard USB port, e.g. power bank, laptop or adapter.  Portable & Practical -- Compact size with a portable storage, easy to operate and to carry around. The application field of carbon dioxide detector is public site, agriculture, animal husbandry, industry, and more.    Specification:  Material: ABS  Display: LCD (4.0TFT 480*320)  Record Groups: 2000 groups  Measuring Range: 0~9999PPM  Resolution: 1PPM  Accuracy: ±40PPM±rdg10%  Temperature Measurement Range: -20~60& 8451;(-4~140& 8457;)  Temperature Measurement Accuracy: ±1& 8451;  Temperature Resolution: 0.1& 8451;  Humidity Measurement Range: 0~100%RH  Humidity Measurement Accuracy: ±3%RH  Humidity Resolution: 0.1%RH  Working Temperature Range: -10~60& 8451;(-14~140& 8457;)  Working Humidity Range: 0~99%RH  Storage Temperature Range: -40~80& 8451;(-40~176& 8457;)  Battery Capacity: 2200mAh  Input: (USB) 5V, 1A  Charging Time: 3 hours  Using Time: >10 hours  Product Size: 140*117*44mm/5.5*4.6*1.7in  Product Weight: 236g/8.3    Packing List:  1 * Carbon Dioxide Detector  1 * User Manual  1 * USB Cable