Grand Seiko Introduces Two Stunning New Spring Drive Models

To commemorate the company's founding 140 years ago, Grand Seiko is adding another two models to its anniversary collection. Both are powered by Caliber 9RA2, the innovative Spring Drive movement that Grand Seiko developed for the occasion. It takes this unique technology to new heights with a slimmer design, thanks to a redesign and repositioning of many parts. Thanks to two mainspring barrels, the caliber has a power reserve of an impressive 120 hours, which it indicates on the back of the watch. The IC has also been updated and comes with a built-in temperature sensor. This allows for an accuracy of around 10 seconds per month.