Smart message and buzzer alarm: Set the temperature alarm range through the smart life app, when the temperature or humidity exceeds the preset value, the temperature will sound for , and the temperature value will flash on the LCD display to remind you. No hub required, connect to 2.4GHz wifi (not support 5G), you can know the sensor's temperature data in real time through Tuya/Smart life app. Backlit LCD Display: The 3-inch LCD display is backlit for easier reading in light conditions Real-time data update and application: with external waterproof probe to monitor temperature to stable connection and low temperature resistance. Operating temperature range up to: -40F to +257F (-40C to +125C). Updates in real time with no , perfect for monitoring refrigerators, freezers, laboratories and plant rooms. Water temperature monitoring is fine. Built-in rechargeable battery: Tuya wireless temperature sensor is powered by DC5V power adapter with USB function. Built-in rechargeable backup battery, when the external power supply is interrupted, the battery can continue to work for 6 hours. The smart temperature sensor with a magnet on the back can be directly attached to the metal surface. 1. App: Tuya Smart/Smart life 2. Powered by: DC5V 1A power adapter (included) 3. Built-in rechargeable battery: 3.7V 600mAH 4. Battery standby time: about 6 hours in full charge 5. Alarm Indication: The digital tube number flashes 6. Detecting temperature: -40 to +120 ( -100 to +170) 7. Detecting Humidity: 0% to 100% 8. Temperature accuracy: 0.5 9. Humidity accuracy:1%RH 10. Measurement deviation: 1 3%RH 11. WIFI band: 2.4G ( not support 5G) 12. Buzzer alarm time: default 13. Size: 77.8mm x 77.8mm x 20.8mm (3.06 x 3.06 x 0.82 inch) Plug Type:US Plug,it applies to Canada, ,Mexico, Thailand, the , the Philippines,Taiwan and so on. Voltage:AC100-240V color:White+black Material:plastic Package Contents: 1 x Tuya WiFi Temperature Detector Alarm Sensor 1 x 3 Meter Sensor Probe 1 x DC5V power adapter with USB Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.