Feature 1、Measurement Per Second: This wireless thermometer is equipped with an excellent microchip and sensitivity sensor that supports real time data updates. Users can also choose the temperature or humidity reporting time, such as 1 second or 100 seconds. 2、Smart Settings: Humidity gauge can be easily operated by mobile APP, you can set the upper and lower limits of temperature and humidity. You can also view historical temperature, humidity and brightness data. Understand how the environment changes at night or when you are not at home (minimum temperature up to: ‑19℃, maximum temperature up to: +60℃). 3、2.9 Inch LCD Display: Data are clearly visible, such as temperature display, humidity display, date display, brightness display, time display. Support temperature unit switching (℃ or °F), completely solve the problem of different units in different countries. 4、Main Function: The room temperature monitoring device has an external temperature sensor probe, you can use it to watch the refrigerator, fish tank, incubator, greenhouse and so on. (probe not included). 5、Self Calibration Required: 1. For calibration accuracy, place the thermohygrometer in the same environment for more than half an hour. (The temperature detecting head should be suspended). 2. Connect the temperature sensing line to the hygrometer, and there is a temperature deviation. 3. Press the setup key three times continuously, and the "drop" prompts to enter the calibration. 4. If two temperature and humidity put together the same temperature, should be calibrated first, and long term placed in the same space. The left intake can not be blocked. Item Type: WiFi Temperature and Humidity Sensor Material: ABS Battery Type: Built in lithium battery (shipped with built in lithium battery) Battery Capacity: 500mAh Weight: Approx. 160.00g/0.4lb Package List 1 x Temperature and Humidity Sensor 1 x USB Cable 1 x English Instruction Manual 2 x Expansion Tubes 2 x Expansion Screws