Features:  Wireless App Control: We uses a Bluetooth 5.0 chip and can easily monitor temperature and humidity data remotely on   app(free downloading from for iOS or for Android App Store via Bluetooth.   Higher Accurate Monitor: Using an accurate and sensitive sensirion temperature and humidity sensor, it can achieve a temperature   error of ±0.5℃(±1℉), a humidity error of ±5%, and refresh once per second for higher accuracy. It can measure indoor high   temperature, low temperature and normal temperature, and the measurement speed is fast and the measurement temperature is accurate.  Data Storage Export: Support temperature data export function, record a group of data every 10minutes, can store up to 100 days of data.   One smart device can be connected up to 100 temperature sensors simultaneously.  Smart Alert for Reminding: The sensor with the buzzer alert on device, if the temperature or humidity is out of range, it will have the alert on   the device. The Alert notification will also be sent to your phone.  Battery Powered: Built in CR2477 large capacity button battery, can be replaced by yourself.   Magnetic Sticker Design: Special magnetic stickers design, can be installed on the wall or door; Space-saving and portable.  Large Display Screen: 3.5-inch large screen display, display interface clear and concise.  Function: Multiple languages can be switched at will, and units can be switched at ℃/1℉ to adapt to the use of global consumers.    Specifications:  Item Type: Wireless Thermometer Hygrometer  Material: ABS  Color: White, Blue  Battery: CR2477 Button Battery(built in)  Temperature Range: -20-65℃(-4-150℉)  Humidity Range: 0-99.9%RH  Bluetooth Version: Bluetooth 5.0  Display Screen Size: 3.5inch  Temperature Measurement Accuracy: ±0.5℃(±1℉)  Humidity Measurement Accuracy: ±5%RH  Size: About 50*50*15mm/1.97*1.97*0.59inch(L*W*H)    Package Includes:   1Pc * Wireless Thermometer Hygrometer