Features:  Air Quality Monitor: Carbon dioxide tester can detect carbon dioxide concentration in the air, it can be widely used in home, classroom, hotel room, apartment, office, gym, etc.  Accurate Sensor: Adopts NDIR detection principle, air convection detection, quickly and accurately detects CO2 in the living environment.  TFT Color Screen: Displays carbon dioxide, air quality level, battery level, temperature and humidity. With 2.8" large TFT screen, clear to read even in dark environment.  Rechargeable Design: Built-in 1500mAh rechargeable lithium battery for long using time, comes with USB cable, quick to charge it via power adapter, power bank, laptop, etc.  Concise Appearance: Simple but stylish appearance, fits in well with different styles of houses. With stable base, easy to be placed on the desktop.    Note:  1. Please read the user manual carefully before use.  2. Size and color may be slightly different due to manual measurement and different lighting conditions. Thanks for understanding.    Specifications:  Color: White  Material: Plastic  Screen: 2.8" TFT Screen  Resolution: 320x240  Input: 5V 1A  Temperature Measurement: Range -7~50℃, Resolution 1℃  Humidity Measurement: Range 0%~99%, Resolution 1%  Detection Principle: NDIR  Carbon Dioxide Test Range: 400-5000PPM  Accuracy: ±30PPM or 3% of Reading  Working Environment: Temperature 0℃~50℃, Humidity＜98%  Built-in Battery: 1500mAh Lithium Battery  Item Size: 135 * 80 * 35mm / 5.31 * 3.15 * 1.38in  Item Weight: 147g / 5.19oz  Package Size: 16 * 10 * 6cm / 6.30 * 3.94 * 2.36in  Package Weight: 215g / 7.59oz    Package List:  1 * Carbon Dioxide Tester  1 * USB Cable  1 * User Manual (English)