Tuya Wifi Wall-mounted Digital Decibel Meter Carbon Dioxide Meter Temperature and Humidity Tester 4in1 Household Multi-functional Environment Air Quality Detector This is an innovative air quality monitor that uses senior information technology to combine sensors with real-time carbon monitoring, capable of detecting carbon dioxide (CO2), decibels, temperature, and humidity in real-time. The LED display clearly shows real-time data and the brightness can be adjusted by yourself. Multifunctional design, with CO2 auto-calibration, automatic data measurement, support manual setting of the CO2 alarm threshold, and overlimit alarm function. Features: 【Multi-functional Integration】: This product is multi-purpose to meet your diverse needs, combining decibel, CO2, temperature, and humidity detection functions in one device. 【LED Display & Adjustable Brightness】: The device adopts a large LED screen design, displaying the carbon dioxide (CO2), decibel, temperature, and humidity at a glance. The LED screen brightness of the device can be manually adjusted to adapt to various environments and meet your personalized needs. The color smiley pattern design on the device is both cute and convenient. 【Auto-calibration】: The device is equipped with a CO2 auto-calibration function to ensure the accuracy of detecting results, so you know the environmental conditions well. 【Automatic Measurement and Over-Limit Alarm】: The device can automatically detect and measure the data, and once it exceeds the set threshold, it will automatically issue an alarm to remind you. Supports the manual setting of CO2 alarm threshold from 800ppm-2000ppm. 【Manual Operation of The Alarm Sound】: To customize the device for your use, you can manually turn the alarm tone on or off as needed. 【Tuya APP Control (Optional)】: With the Tuya APP function, you can view the measurement data on the mobilephone APP, increasing the practicality and convenience. 【Wall-mounted Design】: Wall-mounted design, easy to install, space-saving, and suitable for a variety of environments. Specifications: Name: Decibel Meter  Material: ABS Type: Decibel Meter, Tuya WiFi Decibel Meter  (optional) Display: LED display Battery: 1 * 2000mah rechargeable li-battery (included) CO2 technology: infrared ( NDIR)  Concentration unit for CO2: PPM Detection method for noise: electret condenser microphone Concentration unit for noise: dB Temperature unit: ℃ CO2 detection ranges: 400-5000 ppm CO2 alarm value: 1000ppm CO2 alarm threshold setting: 800ppm-2000ppm Item size: 270 * 118 * 35mm / 10.63 * 4.65 * 1.38in Item weight: 320g / 11.29ounce / 0.71lb Package size: 330 * 100 * 70mm / 12.99 * 3.94 * 2.76in Package weight: 550g / 19.40ounce / 1.21lb Packing List: 1 * Decibel Meter  1 * Charging Cable 1 * Manual