V

Vibration - movement of a pendulum limited by 2 extreme positions.  The balance of a mechanical watch generally makes 5 or 6 vibrations per second (18,000 or 21,600 per hour).   A high frequency watch may make 7, 8 or 10 vibrations per second (25,200, 28,800 or 36,000 per hour). The higher the number of vibrations, the smoother the watch will run.