High Accuracy Sensor - built-in upgraded MEMS sensor, it refreshes once per second to provide more timely and higher accuracy data. Temperature error can to 0.5(1), Humidity error can to 5%. Adopted 5.0 Bluetooth chip, Temperature sensor provides real-time wireless monitoring for temperature (-20-60) and humidity (0-100RH). Upgraded to 50m(164ft) connecting distance (in the open area). Wireless APP Control - temperature sensor uploads data to App when connecting to it via Bluetooth. You can check the maximum and minimum values of temperature and humidity on APP. One smart device can be connected up to 100 temperature sensors simultaneously, and supports Android 4.3 or above, 4s or above. Smart Alert for Reminding - Data on the APP will turn red and will send a notification to your mobile phone to remind you and your family to know the temperature humidity variation when data exceed your pre-set value. It can be applied in monitoring home, pets, refrigerators, freezers, walk-in Cooler, wine cellars and greenhouses. Data Storage Export - Wireless thermometer hygrometer will record data every 10 seconds in the APP, which is total up to100 days. (pls make sure that your phone gets within range of it at least once per day.) Available to download data in CSV format for free after registered account. Mini Portable Design - Our wireless temperature humidity sensor is smaller than others (1.5 x 1.5 x 0.62inches), and built in CR2477 battery, its about 1.3 ounces per one. The battery lifespan is about 10 months. A hanging hole is designed for various placement as you want. Space-saving and handy. Please if any problem about the item and our service, we will try our best to resolve the problem.