The Seiko YT57 Auto-Quartz (Kinetic) movement provides the benefits of both automatic and quartz watches. The automatic movement is the typical rotating counter weight, and is visible via a glass case back. Instead of the rotating mechanism winding a spring, the YT57 stores energy in a small capacitor. This electrical energy is then used to power the quartz operation of the watch; which provides extremely reliable time keeping. This combination of rotation mass converting to electrical energy is a true hybrid approach.