Built-in Rechargeable Battery: Can be powered by external DC5V power supply or standby battery. (Note: If using backup battery, open the back cover and switch on the detector.) Temperature Unit Option: Choose between Celsius or Fahrenheit. View Temperature History: Check past temperature records at any time. Multi-User Support: Share device access with other users via the app. Built-in Buzzer: Sounds an alert when the detector is triggered. Compatible App: Download Tuya Smart or Smart Life app, supports Android and iOS smartphones. Plug Type: EU Plug, suitable for use in countries including Germany, France, Italy, and Indonesia. Voltage: AC100-240V Color: As shown in picture Material: Plastic Package Contents: 1 x Tuya WiFi Temperature Sensor Note: Other items not included. Due to lighting effects and monitor settings, actual color may vary slightly from image. Measurement error allowed within +/- 1-3 cm.