Features High Accuracy And Sensitivity: This Co2 Monitor Is Designed with A High Accuracy Sensor to Measure Co2 Levels And Other Airborne Particles That May Be Harmful to You And Your Family. Real Time Monitoring: This Alarm Equipped Co2 Monitor Alerts You With An Audible Alarm When The Ppm Level Increases (with Support for Turning off The Alarm). You Can Calibrate The Co2 Monitor to Ensure Its Accuracy Over Time. Real Time Monitoring: This Alarm Equipped Co2 Monitor Alerts You with An Audible Alarm When The Ppm Level Increases (with Support for Turning off The Alarm). You Can Calibrate The Co2 Monitor to Ensure Its Accuracy Over Time. Rechargeable Battery: With a micro usb interface charging port and a high capacity 2000mAh battery, you can use our CO2 monitor for a long time without having to change the battery often. Charging the CO2 monitor for 2 hours will ensure 18 hours of use. Portable: This Co2 Detector Is Small And Lightweight, Making It Ideal for Use In The Home, Office, Teachers And Other Controls. The Detector Also Has A Stand on The Back, So It Can Be Placed Indoors on A Desktop, Bookshelf Or Bedside Specification: Item Type: Carbon Dioxide Detector Material: ABS Display: Color LCD Display Time And Date: Manual Adjustment Language: Chinese, English ( Switchable ) Historical Data: 30 Days View Brightness: Adjustable Carbon Dioxide Detection Technology: NDIR Auto Calibration: Automatic Calibration, Also Support Manual Calibration Temperature Unit: Celsius, Fahrenheit ( Switchable ) CO2 Detection Range: 400-5000 ppm (Accuracy 1ppm) CO2 Alarm Value: 800 ppm, Alarm value can be set manually between 800 ppm and 2400 ppm. CO2 Alarm Sound: On And Off Function Atmospheric Pressure: 86Kpa-106Kpa Sampling Time: 1.5s Detection Temperature: -10°C-50°C ( Accuracy ±1°C ) Detection Humidity: 20%-85%RH ( Accuracy ±4%RH) Battery: 1 x 2000mAh Lithium Battery ( Shipped With Built In Battery ) Package List: 1 x Detector 1 x USB Cable 1 x Storage Box Note: Dear customer, please allow for differences (about ±50 ppm) compared to other CO2 meters. After all, different CO2 meters are adapted to different NDIR sensors, so the test results will be different. Thank you for your understanding. Package List 1 x Detector 1 x USB Cable 1 x Storage Box