High Accuracy Sensor: - Built-in MEMS sensor, it refreshes once per second to provide more accurate and faster data. Temperature error can within 0.5 (1), humidity error can within 5%. Adopted Bluetooth 5.0 chip, the temperature sensor provides real-time wireless monitoring of temperature (-20-60) and humidity (0-99RH). APP control Without Wire: - Temperature Sensor uploads data to APP when connecting via Bluetooth. You can check the max and min values of temperature and humidity on APP from your phone. Support Android 4.3 or above, or above smart device. Also, you can see the temperature and humidity on this 1.5 inch screen. Free download APP from App Store or Google Play Smart Alert for Reminder: - The data on APP will turn red to remind you and your family to know the variations of temperature and humidity and make some changes over time when the data exceeds your preset value. and the alert will be sent to APP. It can be applied in home monitoring, pets, refrigerators, freezers, walk-in coolers, wine cellars and greenhouses, etc. Data Storage Export: - Thermometer hygrometer wireless will record data every 10 mins in APP, which is total up to 100 days. Available to download data in CSV format for free after registered account. We offer one year warranty. If you have any questions, please feel free to contact us, we will do our best to provide you with a satisfactory solution. Design Mini & Portable: - The wireless temperature humidity sensor is smaller than others. Built in CR2477 batteries, battery life is about 1 year, you can replace the battery by yourself after it runs out. A hanging hole is designed for various locations as you like. There is a button on the back of the sensor