Mechanical Movement: NO need to use BATTERY, but AUTOMATICE SELF-WINDING! ( How to wind up: 1. Pull the watch crown out, then rotate the pointer clockwise to your local time. 2. Press the crown in and swing up the crown by 10-15 rounds, then you could see the winding wire line is tight. 3. Then you need to shake the watch by 3-4 times with big force by hand.