{"product_id":"evolution-9-spring-drive-u-f-a-ushio-300-diver-slgb025","title":"Evolution 9 Spring Drive U.F.A. Ushio 300 Diver SLGB025","description":"In 2025, Grand Seiko unveiled the Spring Drive Caliber 9RB2, a groundbreaking movement that received the then-new U.F.A. designation, standing for “Ultra Fine Accuracy.” Boasting an annual accuracy rate of ±20 seconds, Caliber 9RB2 earned the distinction of being the most accurate wristwatch movement powered by a mainspring.* This model is powered by Caliber 9RB1, featuring an improved construction that makes it ideal for sporting conditions while sharing the same attributes as the Caliber 9RB2.\r\u003cbr\u003eThe term ushio, which means “tide” in Japanese, evokes the waters that surround the Japanese archipelago. The green dial draws from the tranquil beauty of shallow coastal waters near the shore.\r\u003cbr\u003e* As of April 2026, based on Grand Seiko’s research.\r\u003cbr\u003e\r\u003cbr\u003eExterior\r\u003cbr\u003eExterior: High-Intensity Titanium\r\u003cbr\u003eCase back: Screw case back\r\u003cbr\u003eGlass Material: Sapphire crystal\r\u003cbr\u003eGlass Coating: Anti-reflective coating on inner surface\r\u003cbr\u003eLumiBrite: LumiBrite on hands, index(es) and bezel\r\u003cbr\u003eCase size: Diameter 40.8mm Lug-to-lug 48.5mm Thickness 12.9mm\r\u003cbr\u003eBand width:\t21mm\r\u003cbr\u003eClasp type: Locking extension clasp with micro-adjustment\r\u003cbr\u003eThe perimeter of Band: 195mm\r\u003cbr\u003eMovement\r\u003cbr\u003eCaliber no.: 9RB1 Instructions\r\u003cbr\u003eMovement Type:\t Spring Drive\r\u003cbr\u003ePower reserve:\tApprox. 72 hours(3 days)\r\u003cbr\u003eAccuracy: ±20 seconds per year (±3 seconds per month)\r\u003cbr\u003eFunctions\r\u003cbr\u003eWater resistance: 300m \/ 1000ft diver's\r\u003cbr\u003eMagnetic resistance: 4,800 A\/m\r\u003cbr\u003eWeight:\t122 g\r\u003cbr\u003eOther details \/ Features:\t\r\u003cbr\u003eUnidirectional rotating bezel\r\u003cbr\u003eScrew-down crown\r\u003cbr\u003eAllergy-safe metal\r\u003cbr\u003e33 jewels\r\u003cbr\u003ePower reserve indicator","brand":"Grand Seiko","offers":[{"title":"Default Title","offer_id":57771020517708,"sku":"GSKRL00083","price":12500.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0472\/5843\/5733\/files\/SLGB025G.png?v=1781190792","url":"https:\/\/davidrosas.com\/products\/evolution-9-spring-drive-u-f-a-ushio-300-diver-slgb025","provider":"David Rosas","version":"1.0","type":"link"}