Grand Seiko Kodo Constant-Force Tourbillon (SLGT003, SLGT001, SLGT005): Specs, History, Value | Ultimate Watch

The Grand Seiko Kodo Constant-Force Tourbillon is the watch that ended the argument about whether Grand Seiko belonged in the same room as the Swiss haute horlogerie houses. Kodo means heartbeat in Japanese, and the reference SLGT003 was the first time in the brand's history, going back to 1960, that Grand Seiko put a mechanical complication of this order on the market. It carries the caliber 9ST1, a manual-wind movement that combines a tourbillon and a constant-force mechanism on a single axis, a construction that had never been done before in a production watch. The case runs 43.8mm across, 12.9mm thick, built from platinum 950 and Grand Seiko's Brilliant Hard Titanium, water resistant to 100m, and it was released in October 2022 as a boutique-exclusive limited edition of 20 pieces at roughly US$350,000. This is not a watch that trades on 47th Street every week; there were only 20 SLGT003 made and a handful of siblings. But when a Kodo does come across the counter, or when a client asks us what one is worth, we want the file to be as deep as the watch deserves. We buy and sell serious independent and haute horlogerie regularly at Ultimate Watch, and the Kodo is exactly the kind of piece where knowing the caliber, the production numbers, and the auction record separates a real offer from a guess.