PTH-9CW Wifi Intelligent Infrared CO2 Detector Air Quality Detector Home Temperature And Humidity Meter 1. WiFi connection, temperature, humidity, carbon dioxide, buzzer alarm, Tuya Smart 2. When the carbon dioxide concentration reaches the preset value, the buzzer will alarm 3. Applicable to a variety of scenarios, real-time monitoring, in the car, public places, offices, bedrooms 4. Back hook, easily fixed in the air 5. Temperaturehumidity dual detection, cold, warm, dry and wet, clear at a glance 6. Temperature range: -10 to 40 degrees Celsius 7. Measuring range: 40 square meters 8. Battery capacity: 2400mah 9. Power supply mode: TYPE-CUSB-C chargingbuilt-in lithium battery 10. Charging voltage: 5V1A 11. Dimensions: 98 x 90 x 40mm Manual calibration: 1. Press and hold three keys at the same time in the off state 2. Enter the calibration state, and the screen will display a 200-second countdown 3. Calibration is successful