[Wireless APP Control and Smart Alerts] The temperature sensor uploads data to the APP when connected to the app via Bluetooth. You can set the monitor range. When the data is outside the preset range, the data on the application is shown in red. [Data storage Output] Every 10 minutes, a total of up to 100 days of data is stored inside the device, make sure your phone comes within its range at least once a day. High Precision sensorThe sensor uses a high-end Bluetooth 5.0 chip. Temperature range :-20-60 C (-34-140F) Humidity range: 0-99%RH. Built-in MEMS sensor for high-precision monitoring. Temperature deviation :0.5(1); Humidity deviation :3% relative humidity. Data is automatically updated every second. The connection distance can be up to 20 meters (65.6 ft)(accessible). [Mini Size and Battery type] Smaller size :(1.3 x 1.3 x 0.47) inches. With a hanging hole, can be placed at will. If there is any problem with the use or function of the product, or the product is defective/damaged, please contact the seller first, we will try our best to solve the problem for you.