Built-in rechargeable battery: Can be powered by external DC5V power supply or standby battery. (Note: To power the detector via backup battery, open the back cover and switch on the detector.) Temperature unit is optional (Celsius or Fahrenheit). Check the history record of temperature anytime. Multi-user supervision supported: You can share the device with other users. Built-in buzzer: The buzzer will sound when the detector is triggered. APP: Download the Tuya Smart or Smart Life app, compatible with Android and iOS smartphones. Plug type: EU plug, suitable for use in Indonesia, Germany, France, Italy, and other regions. Voltage: AC100-240V Color: As shown Material: Plastic Package contents: 1 x Tuya WiFi Temperature Sensor Only the above package content is included; other products are not included. Note: Light reflection and different displays may cause slight variations in color between the image and the actual item. Measurement error allowance: +/- 1-3 cm.