Watches & Wonders 2026: Grand Seiko SLGB006 “Ice Forest at Dawn” and the Most Precise Spring-Driven Movement in the World

At Watches & Wonders 2025, Grand Seiko introduced a significant development in the rate accuracy of its spring-driven wristwatches: with the automatic Calibre 9RB2, the brand presented what it describes as the most precise movement of its kind currently in existence. One year later, on the occasion of Watches & Wonders 2026, this calibre makes its debut in a limited edition featuring a yellow-gold case—marking the first time it has been housed in such a material. The dial draws inspiration from the frost-covered forests of the Shinshu region, where the movement originates. What follows is a closer look at the Grand Seiko SLGB006 „Ice Forest at Dawn“ and its Calibre 9RB2.

The Spring Drive Calibre 9R65: the most precise spring-driven movement in the world

With the Spring Drive movement—patented in the late 1970s and first presented in 1988—Grand Seiko pursues a method of rate regulation that differs fundamentally from the mechanical solutions employed by its Swiss counterparts. Instead of a traditional escapement, it utilises a so-called glide wheel, which is regulated and braked by a quartz oscillator and an electronic control circuit. Notably, the entire Spring Drive system operates without a battery, with the quartz module being powered purely mechanically via the mainspring. In 2004, this construction culminated in the Spring Drive Calibre 9R65. This calibre introduced a key distinction from earlier movements of the brand: it combined automatic winding and a power reserve of 72 hours with a regulating system capable of achieving a monthly rate accuracy of ±15 seconds.

In 2025, at Watches & Wonders, Grand Seiko presented the next major evolution of its Spring Drive movement: the automatic Calibre 9RB2 with a power reserve of 72 hours, which is also used in the new Grand Seiko SLGB006 „Ice Forest at Dawn“. Bearing the designation ‘Spring Drive UFA’—with ‘UFA’ standing for ‘Ultra Fine Accuracy’—the Calibre 9RB2 achieves a precision of ±20 seconds, not per day, week or month, but per year. With this level of accuracy—equivalent to approximately ±3 seconds per month and thus 12 seconds more precise than its predecessor—Grand Seiko laid claim to having developed the most accurate movement powered by a mainspring.

This high level of precision of ±20 seconds per year (approx. ±3 seconds per month) is based on an in-house manufactured quartz oscillator, whose frequency is stabilised over a period of three months. It is then vacuum-sealed together with a newly developed, energy-efficient integrated circuit in order to minimise external influences. Temperature compensation also plays a decisive role: prior to assembly, each quartz crystal is measured at different temperatures, enabling the movement to counteract even the smallest thermal variations that would otherwise affect its accuracy.

The design and construction of the new Grand Seiko SLGB006 „Ice Forest at Dawn“

Since 2004, Spring Drive models have been manufactured by the watchmakers of the Shinshu Watch Studio, located in Shiojiri, a city in Nagano Prefecture. It is here, within these functionally designed workshops, that each index is applied to the dial by hand, every Spring Drive calibre of the 9R family is brought to life by steady hands, and each case is finished to a mirror polish in accordance with the principles of Zaratsu polishing. The Shinshu Watch Studio is situated in a mountainous region of Japan known for its harsh winters—conditions that also served as the inspiration for the dial of this new model, aptly named “Ice Forest”. Not far from the studio lie the Kirigamine Highlands, renowned for their so-called “ice forests”, where larch trees become coated in ice on particularly cold days, reflecting the light of the early morning dawn.

Grand Seiko captures this winter landscape of the Kirigamine Highlands in the “Ice Forest” dial by drawing on the Japanese design principle of mitate, in which a scene is not depicted literally, but rather interpreted through colours, forms, and surface textures. In the case of the Grand Seiko SLGB006 „Ice Forest at Dawn“, the scenery is expressed through a surface featuring a fine pattern with a subtle gradient in deep black, overlaid with numerous reflective particles. Set against this dark backdrop are gold-coloured indices and hands, intended to evoke the warm tones of the rising sun.

The case of the Grand Seiko SLGB006 „Ice Forest at Dawn“, measuring 37 mm in diameter, marks the first time that a model of the Evolution 9 collection in this size has been executed in 18-carat yellow gold. It is paired with a black crocodile leather strap and a matching triple-folding clasp in yellow gold with a push-button release. The case, fitted with a screw-down sapphire crystal caseback, measures 11.4 mm in height and offers water resistance to 100 metres (10 bar).

Price & availability of the Grand Seiko SLGB006 „Ice Forest at Dawn“

Limited to 80 pieces, the Grand Seiko SLGB006 „Ice Forest at Dawn“ will be available exclusively through Grand Seiko boutiques from June 2026. The price is set at €44,700.

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