A standard spring-loaded model that has had a huge following since its launch. It was the first Grand Seiko watch powered by a spring winding, the third movement mechanism, which combines the driving force of a mainspring found in mechanical watches with the high precision of a quartz watch. In the spring winding, the second hand moves in a perfect sliding motion that reflects the constant and natural flow of time. It has a 72-hour power reserve and a power reserve indicator on the lower left of the dial. The face of the watch and the faceted hands and hour markers seem to change with the angle and amount of light, giving this watch its everlasting charm. The wearer of this watch can enjoy a clear view of the movement through the transparent caseback.