Features: 3 in 1 Function: CO2 / temperature/ humidity tester. Multifunction carbon dioxide monitor cares for your health and can be widely used in home, office, market, classroom, hotel, car, cellar, greenhouse, warehouse, lab, etc. 3.5-inch Digital Screen: Displays CO2, air quality level (by 3-color expressions), temperature, humidity and battery level. Large digital color screen for easy and clear reading even in dark environments. Carbon Dioxide Tester: Adopts NDIR sensor and air convection detection, quickly and accurately detects CO2 concentration, ambient temperature and humidity in the living environment. Air Quality Level Indication: Excellent, 400-800PPM (Green); Good, 800-1800PPM (Yellow); Poor, 1800-5000PPM (Red). 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, place it on the desktop or wall mounted installation, 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: 3.5-inch Digital Color Screen Sensor: NDIR Sensor CO2 Detection Range: 400-5000PPM Accuracy: 70PPM 3% Reading Temperature Measurement Range: -10~50 Accuracy: 0.1 Humidity Measurement Range: 0-99.9% RH Accuracy: 3%RH Response Time: about 10s Repeatability: 0.5% Power Supply: 5V 1A Max. Power Consumption: 500mA Built-in Battery: 3.7V 1200mAh Lithium Battery Work Condition: 0-50, 0-90%RH (Non-condensing) Storage Temperature: 16-30 Item Size: 98 * 66 * 30mm / 3.86 * 2.60 * 1.18in Item Weight: 138g / 4.87oz Package Size: 12 * 5 * 8cm / 4.72 * 1.97 * 3.15in Package Weight: 220g / 7.76oz Package List: 1 * CO2 Tester 1 * USB Cable 1 * User Manual (English)