Features:  5 in 1 Function -- CO2/ HCHO (formaldehyde)/ TVOC/ temperature/ humidity tester. Multifunction air quality monitor cares for your health and can be widely used in home, office, market, classroom, hotel, car, cellar, greenhouse, warehouse, lab, etc.  6.5-inch Digital LED Screen -- Displays CO2, air quality level (3-color LED), HCHO (formaldehyde), TVOC (organic gas), temperature, humidity, date, time and battery level. Large digital color screen for easy and clear reading even in dark environments.  Air Quality Tester -- Adopts sensitive NDIR sensor and air convection detection, quickly and accurately detects CO2, formaldehyde and TVOC concentration, ambient temperature and humidity in the living environment.  3-Color LED Indicator, Alarm Buzzer -- Healthy, 400-800PPM (Green); Worse, 801-1800PPM (Yellow); Serious, 1801-5000PPM (Red), at the same time, the alarm will start and last for 10s. Clear at a glance, old people and children can easily recognize too.  Rechargeable Battery -- Built-in 1200mAh lithium battery, strong endurance and easy recharging. Simple but stylish appearance, just place it on the desktop, it fits in well with different house styles.    Note:  1. Please read the user manual carefully before use.  2. Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding.    Specifications:  Color: White  Material: ABS + Electronic Components  Screen: 6.5-inch Digital LED Screen  Sensor: NDIR Sensor  CO2 Detection Range: 400-5000PPM  Accuracy: ±(50PPM+5% Reading)  HCHO Detection Range: 0.005-2mg/m³  TVOC Detection Range: 0.008-2mg/m³  Temperature Measurement Range: 1~70℃  Accuracy: ±1℃ (0~65℃)  Humidity Measurement Range: 0-99% RH  Accuracy: ±2%RH  Response Time: ＜2min  Built-in Battery: 3.7V 1200mAh Lithium Battery  Work Condition: 0-50℃, 20-90%RH (Non-condensing)  Item Size: 160 * 41 * 90mm / 6.30 * 1.61 * 3.54in  Item Weight: 235g / 8.29oz  Package Size: 18.5 * 5 * 11.5cm / 7.28 * 1.97 * 4.53in  Package Weight: 406g / 14.32oz    Package List:  1 * Air Quality Tester  1 * USB Cable  1 * User Manual (English, Japanese, German, French, Spanish, Chinese)