The Clock requires Plug power to work. (Plug is Not included) The button battery is only for data keeping when DC power suddenly gone. >>>Package includes: Clock * 1 USB power Cable * 1 Vibrator * 1 Instructions Manual * 1 >>>FEATURES: 1, Vibrating clock with powerful vibrator 2, Super loud alarm rings. 3 levels of volume for choose 3, Brightness adjustable among 4 levels 4, Dynamic RGB Led Display and several single color light modes switchable 5, Dynamic RGB Atmosphere Night Light and several single color light modes switchable 6, Four wake-up modes : Loud Buzzer, Vibrator, Red Blinking Light, or Combine them all 7, Dual Alarms with Snooze function 8, display Time: 12HR / 24HR 9, display Temperature (℃ / ℉) 10, display Calendar and the day of week 11, Memory function >>>Parameter: * Accuracy of temperature measuring: +/- 2℃ * Net Weight: 0.182kg * Clock size L*W*H(cm): 24.4 * 1.53 * 7.4 (cm) * Power: DC Power (Plug is Not Included)