At Watches & Wonders 2024, Grand Seiko announced the new 9SA4 caliber and the first two watches featuring it, the SLGW002 and SLGW003. As a refresher, the 9SA4 is a manual hi-beat (36,000 bph), 80-hour, time-only caliber featuring their in-house dual-impulse escapement, first seen in the 9SA5. With a power reserve on the back of the movement, beautiful bridge designs and finishing, and a unique “wagtail-bird-shaped” winding click, it set a new bar for Grand Seiko’s mechanical calibers. But, perhaps just as exciting as the movement itself was that the watches featuring it were sized at an idyllic 38.6mm diameter and 9.95mm thickness with a 20mm lug, addressing the naysayer’s concerns around Grand Seiko’s sizing.
While a pair of fantastic releases, since introduction, we have been wondering where we will see this movement next. Well, we just got our answer, and I have to tell you, I’m equally surprised and delighted. They went vintage rather than with the new case and a different dial, which would have been most expected. Yes, they decided to bring back, as a limited edition, of course, a “recreation” of the 45GS from 1968. A little history, the 45GS came out a year after the 44GS and featured the same case design, but differed in that it featured the brand’s first hi-beat manual wound movement, the 4520.
The 44/45GS case defines the Grand Seiko “Grammar of Design” as set out by Taro Tanaka, with flat, Zaratsu polished flanks, and an overall faceted shape that is unique to the brand. The DNA of these cases has persisted in the modern Grand Seiko collection, specifically in the 44GS Heritage models in 40mm and 36.5mm sizes, featuring nearly every movement Grand Seiko makes.