Self-winding movement, 1.spring stores energy and provides power. Please wind it manually when you first wear it (rotate the crown Clockwise about 35 turns),2. If the wearing time is less than 8 hours per day/or working in the office, we recommend manual winding every day before going to bed,3.manually wind or shake your arm to replenish energy.If it is placed in one place for a long time, it will stop working