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 is optional (Celsius or Fahrenheit). View temperature history records at any time. Supports multi-user supervision: Share the device with other users via the app. Built-in buzzer sounds when the detector is triggered. Compatible with Tuya Smart or Smart Life app. Available for Android and iOS smartphones. Plug type: EU plug, suitable for use in countries including Germany, France, Spain, Italy, and Indonesia. Voltage: AC100-240V Color: As shown 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.