Grand Seiko Spring Drive Caliber 9RB2 Ultra Fine Accuracy SLGB003 Watch - Evolution 9

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.

Exterior:

Case Material: High-intensity titanium

Case back: See-through and 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

The perimeter of Band:190mm

Movement:

Caliber No: 9RB2

Movement Type: Spring Drive

Power Reserve: Approx. 72 hours

Accuracy: ±20 seconds per year (±3 seconds per month)

Features:

Water Resistant - 10 bar

Magnetic resistance: 4,800 A/m

Weight: 100 g

Screw-down crown

Allergy-safe metal

34 jewels

Power reserve indicator

Grand Seiko Style #: SLGB003