Spring Drive 8 Day Power Reserve

Caliber 9R01

To maintain perfect timekeeping for up to eight days (192 hours) requires greatly increased power, which is provided by a linked series of three barrels. This remarkable caliber, 9R01, has also been designed throughout to maximize energy efficiency, reducing friction between parts that would otherwise lead to loss in the transmission of the energy derived from the mainspring.

On the back, a sapphire case back allows a clear view of the exquisite finishing of the one-piece bridge, the rubies and the power reserve indicator. In the assembly of most watch movements, the gears and other components are placed on the main plate which acts as a base and these parts are then held in place on the main plate by several bridges. For Caliber 9R01, however, Grand Seiko developed a unique system using a single, one-piece bridge. This system delivers enhanced durability and is, we believe, a unique design.

The thickness of this one-piece bridge is some three times greater than any other Spring Drive caliber. Made possible by very high precision engineering, it provides a totally solid base on which all the components are secured in place more precisely. The bridge traces the outline of Mt. Fuji and the highly polished rubies and tempered blue screws evoke the lights of the city of Suwa below the Studio’s home.


* In an actual product, the case back direction might be different from the photograph.

A sharp finished case achieved by our special Zaratsu technique

The case of SBGD201 is made of platinum 950, and SBGD202 is made of 18k rose gold.

These cases can be polished to a sparkling mirror finish with our specially adapted Zaratsu technique.

The dials, glisten with a subtle and unusual beauty.

The dials are remarkable. Like the diamond-dust sparkle of snow that shimmers in the morning light in the clear mountain air of the area around the Micro Artist Studio, the dial of SBGD201 glistens with a subtle and unusual beauty.

Inspired by the night sky in the mountains that surround the studio, SBGD202 presents an entirely different view of the beauty of Japan. A black dial through which the stars twinkle just as they do on a clear dark night in central Japan, adding extra depth and richness to the dial.

Thanks to a special process, the dials have a fascination all of their own. They are at once sparkling, mysterious and yet perfectly legible.

The work of the Micro Artist Studio

These Grand Seiko Spring Drive 8 Day Power Reserve watches are created by the Micro Artist Studio
in Seiko’s facility in Shiojiri in the Nagano prefecture of central Japan.

Known until now mainly for its Spring Drive Minute Repeater, Sonnerie and Eichi watches for Credor,
the Micro Artist Studio is proud to contribute to the growing reputation of Grand Seiko
and has developed a remarkable Spring Drive caliber that offers an eight-day power reserve
with the Studio’s trademark quality of materials and finishing.


Spring Drive 8 Day Power Reserve






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Please confirm the availability of models to each store.