High Accuracy Sensor - Built-in upgraded MEMS sensor refreshes once per second to provide timely and accurate data. Temperature accuracy is within ±0.5°C, humidity accuracy is within ±5%. Features a Bluetooth 5.0 chip for real-time wireless monitoring of temperature (-20°C to 60°C) and humidity (0-100% RH). Offers an extended connection distance of up to 50 meters (164 feet) in open areas. Wireless APP Control - The temperature sensor uploads data to the app when connected via Bluetooth. View maximum and minimum temperature and humidity values on the app. One smart device can connect up to 100 sensors simultaneously. Compatible with Android 4.3 and above, iPhone 4s and above. Smart Alert Function - The app will display data in red and send a notification to your phone when readings exceed your preset thresholds, alerting you to changes in temperature or humidity. Suitable for monitoring homes, pets, refrigerators, freezers, walk-in coolers, wine cellars, and greenhouses. Data Storage and Export - The wireless thermometer hygrometer records data every 10 seconds within the app, storing up to 100 days of history (ensure your phone is within range at least once daily). Data can be exported in CSV format for free after account registration. Compact and Portable Design - This wireless temperature and humidity sensor measures 1.5 x 1.5 x 0.62 inches, weighs approximately 1.3 ounces, and includes a built-in CR2477 battery with an estimated lifespan of 10 months. A hanging hole allows for flexible placement. Space-saving and convenient. if you have any issues; we are committed to customer satisfaction.