A37 Digital Carbon Dioxide Detector CO2 Monitor Portable Air Quality Monitoring Tester Item Type: Carbon Dioxide Detector Material: ABS Color: As shown in the picture Product Size: Approx.55x75x130mm / 2.17x2.95x5.12in Model: A37 Range: 400~5000ppm Measuring Temperature: -10~50℃ Relative Humidity: 0-99%RH Sensor Type: CO2 sensor based on NDIR principle ABC Function: Automatic baseline calibration (continuous power-on work for more than 3 days) Audible Alarm: Buzzer BiBi sound alarm Light Alarm: Red backlight flashes Temperature and Humidity: Display the temperature and humidity of the current environment Display Mode: LCD numerical display Low Voltage Reminder: The battery symbol flashes during low battery time Automatic shutdown: when battery powered, it will automatically shut down if there is no operation for 2 hours Backlight: White backlight; it will automatically turn off in about 20 minutes Operating Environment: 0~50℃, 0~85%RH Storage Environment: -20~60℃, 0~95%RH Power Supply: Rechargeable lithium battery 3.7V 1500mAh (built-in battery) Adapter Requirements: Built-in lithium battery, users can use the adapter for charging or power supply. Adapter Specifications: USB output interface, input voltage: 5V DC, output current: 1A, please use qualified adapters that conform to relevant safety certifications (such as CCC, UL, FCC, etc.) for charging. How e: Get the product, long press the power button to turn it on, wait for the buffer time, enter the measurement interface, the LCD screen will display CO2 concentration, current environmental temperature, relative humidity, current date/time and other information. Simple e and easy to operate, it is a good helper necessary for the home.