The Spring Drive U.F.A. movement with an astounding annual rate makes its debut in a creation inspired by the beauty of ice forests
SLGB003
Evolution 9 Collection
Jun. 2025 Release
Features
The pursuit of high accuracy has been the cornerstone of Grand Seiko’s values since its first watch was created in 1960. In the late 1970s, the development of Spring Drive began with an aim to harmoniously blend the traditional energy of a mainspring with state-of-the-art electronic watchmaking advancements. In 2004, Grand Seiko introduced the Spring Drive Caliber 9R65 with a monthly rate of ±15 seconds. Today, this legacy of accuracy in watchmaking reaches new heights with the announcement of the Spring Drive Caliber 9RB2, which receives the new U.F.A. designation, standing for “Ultra Fine Accuracy.” The groundbreaking movement boasts a level of precision defined not by accuracy in seconds per day, week, or month, but by its accuracy over one year. The automatic U.F.A. movement has an astounding annual rate of ±20 seconds, making it the most accurate wristwatch movement powered by a mainspring today.* *As of April 2025, based on Grand Seiko’s research.
In 2025, the Caliber 9RB2 makes its debut in the Evolution 9 Collection. To the east of the Shinshu Watch Studio lie the Kirigamine Highlands, where frost-covered trees can be observed during harsh winter months. The intricately textured dial captures the beauty of these ice forests thanks to finishing techniques that create pale blue tones that are subtle yet striking in their presence.
Specifications
Exterior: | High-intensity titanium |
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Case back: | See-through & Screw case back |
Glass Material: | Box shaped sapphire crystal |
Glass Coating: | Anti-reflective coating on inner surface |
Case size: | Diameter 37.0mm Lug-to-lug 44.3mm Thickness 11.4mm |
Band width: | 20mm |
Clasp type: | Three-fold clasp with push button release and micro-adjustment feature |
Caliber no.: | 9RB2 Instructions |
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Movement Type: | Spring Drive |
Power reserve: | Approx. 72 hours(3 days) |
Accuracy: | ±20 seconds per year (±3 seconds per month) |
Water resistance: | 10 bar |
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Magnetic resistance: | 4,800 A/m |
Other details / Features: |
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Astonishing accuracy
The new movement achieves its ±20-seconds-per-year accuracy thanks to new and enhanced manufacturing and processing methods for the three-month-aged quartz oscillator, and a newly designed IC. And, as with the 9RA series of Spring Drive movements, the frequency of each individual quartz oscillator is measured at several different temperatures, with the resulting data necessary for thermo-compensation programmed into the low-power IC. Both the oscillator and sensor are vacuum-sealed to minimize temperature differences and protect against external factors such as humidity, static electricity, and light, ensuring precise temperature adjustments and the stable performance of the quartz oscillator. In addition, for the first time in Spring Drive, the new movement features a regulation switch that can be used during after-sales service to correct any divergences in accuracy that may occur over long periods of use.Dial inspired by the ice forests
The dial with pressed pattern inspired by the beauty of ice forests has a silver-tinged blue hue, evoking the ice forests seen through crisp, clear air, and is beautifully accented by a tempered blue seconds hand. Thanks to the movement’s compact design, the new watches have a case diameter of just 37mm, making them the smallest models powered by the 9R series to date and ideal for smaller wrists.Newly developed three-step micro-adjustment clasp
It features a newly developed three-step micro-adjustment clasp that operates without a tool, allowing precise adjustments in 2mm increments for enhanced comfort.
Movement finishing reflecting the natural beauty of Shinshu
The movement's beauty is revealed through the sapphire crystal case back, with mirror-polished, beveled edges adding brilliance. Its design, inspired by the natural surroundings of the Shinshu Watch Studio where it is made, reflects a uniquely Japanese aesthetic characterized by understated charm and elegance. The jewels echo the glittering stars that sparkle during the early days of winter above the surrounding mountains, and the delicate texture of the movement’s surfaces reflects the frost that winter brings to the trees of Shinshu, where all Grand Seiko Spring Drive watches are made.The Spring Drive U.F.A. caliber with an astounding annual rate
The pursuit of high accuracy has always been the cornerstone of Grand Seiko’s values. Receiving the new U.F.A. designation, which stands for “Ultra Fine Accuracy,” Caliber 9RB2 boasts a level of precision defined not by accuracy in seconds per day, week, or month, but by accuracy over one year. The movement has an astounding annual rate of ±20 seconds, or approximately ±3 seconds per month.Option strap

Strap
XGL00120
Band width: | 20mm |
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Clasp width: | 18mm |
Color: | Black |
Material: | Crocodile |
- Available at the Grand Seiko Boutiques and selected Grand Seiko Salons
Strap
XGL00320
Band width: | 20mm |
---|---|
Clasp width: | 18mm |
Color: | Brown |
Material: | Crocodile |
- Available at the Grand Seiko Boutiques and selected Grand Seiko Salons
Strap
XGL00520
Band width: | 20mm |
---|---|
Clasp width: | 18mm |
Color: | Navy |
Material: | Crocodile |
- Available at the Grand Seiko Boutiques and selected Grand Seiko Salons
Strap
XGL00720
Band width: | 20mm |
---|---|
Clasp width: | 18mm |
Color: | Light blue |
Material: | Crocodile |
- Available at the Grand Seiko Boutiques and selected Grand Seiko Salons
Strap
XGL00920
Band width: | 20mm |
---|---|
Clasp width: | 18mm |
Color: | Elegant light green |
Material: | Crocodile |
- Available at the Grand Seiko Boutiques and selected Grand Seiko Salons
Strap
XGL01120
Band width: | 20mm |
---|---|
Clasp width: | 18mm |
Color: | Warm orange |
Material: | Crocodile |
- Available at the Grand Seiko Boutiques and selected Grand Seiko Salons
Strap
XGL01320
Band width: | 20mm |
---|---|
Clasp width: | 18mm |
Color: | Light gray |
Material: | Crocodile |
- Available at the Grand Seiko Boutiques and selected Grand Seiko Salons