The Essence of Grand Seiko is expressed in each type of watch, Mechanical, Quartz, and Spring drive.

9S Mechanical Caliber Series
Since 1895 when Seiko built its first mechanical watch, the history of Seiko's mechanical watchmaking is a story of ever-increasing accuracy and reliability. The 9S series continues this tradition and is the best mechanical watch Seiko has ever built.
9F Quartz Caliber Series
Since the introduction of the world's first quartz watch in 1969, Seiko has constantly led the world in quartz innovation, with many world-first creations including the first quartz chronograph in 1983 and Seiko Kinetic in 1988.
Caliber 9F pushes back the limits of quartz once more, and it might just be the best quartz watch ever built.
9R Spring Drive Caliber Series
With its glide motion hands, Spring Drive is the only watch in the world to reflect the true, continuous nature of time.