{"product_id":"良品-seiko-セイコー-1971年-グランドセイコー-grand-seiko-hi-beat-デイト-自動巻-automatic-25石-ref-5645-7000-保あり-oh済","title":"Good condition [SEIKO] Seiko 1971 Grand Seiko GRAND SEIKO hi-beat Date Automatic 25 jewels Ref. 5645-7000 With warranty, overhauled","description":"\u003cp\u003e\u003cbr\u003e【1971 - 56GS】Grand Seiko Hi-Beat – Ref. 5645-7000 Overhauled\u003c\/p\u003e\n\u003cp\u003e 【Product Features】\u003cbr\u003eThis is a 1971 \"56GS (56 Grand Seiko)\".\u003cbr\u003eIt is known as the last automatic winding series in the history of vintage Grand Seiko, which dates back to the 1960s.\u003cbr\u003eIt features a sharp case design that inherited the \"Seiko Style\" and a high-precision hi-beat movement (28,800 vibrations). The beautiful patina on the dial, which has appeared after 50 years, tells the unique history of this particular timepiece.\u003c\/p\u003e\n\u003cp\u003e【Operation Checked \u0026amp; Cleaned】\u003cbr\u003eWhen acquired, this watch had insufficient amplitude and a faulty date change.\u003cbr\u003eIt has been repaired and overhauled in-house. Gaskets have been replaced.\u003cbr\u003eTo ensure our customers can use it with peace of mind, we have conducted a 48-hour operation check and cleaned it before listing.\u003cbr\u003eTimegrapher measurements show a **daily rate of -12 to -17 seconds and an amplitude of 283 degrees**, maintaining extremely stable accuracy for a timepiece that is half a century old.\u003cbr\u003eComes with a 1-year operational warranty from the date of arrival (Japan domestic warranty).\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e 【Key Specifications】\u003cbr\u003eBrand: GRAND SEIKO\u003cbr\u003eModel: 56GS\u003cbr\u003eModel Number (Reference): 5645-7000\u003cbr\u003eManufacturing Year: 1971\u003cbr\u003eSerial Number: 12**\u003cbr\u003eMovement: Automatic (Cal. 5645A \/ Hi-Beat)\u003cbr\u003eCase Size: Approx. 36mm (width) \/ Approx. 41.8mm (height) \/ Approx. 10.7mm (thickness)\u003cbr\u003eDial Color: White (excellent condition)\u003cbr\u003eMaterial: Stainless Steel\u003cbr\u003eFunctions: Date display, Hacking function (second hand stop)\u003cbr\u003eWrist Size: Max. approx. 19cm\u003cbr\u003eStrap: SEIKO leather strap (non-original, unused)\u003cbr\u003eAccessories: None (watch body only)\u003c\/p\u003e\n\u003cp\u003e---\u003c\/p\u003e\n\u003cp\u003e Condition Details\u003cbr\u003eAccuracy: Daily rate -12 to -17 seconds \/ Beat error 0.0ms \/ Amplitude 283 degrees (excellent reference values)\u003c\/p\u003e\n\u003cp\u003e《Condition Details》\u003cbr\u003e・Glass: Very minor scratches, good condition\u003cbr\u003e・Case: Minor scratches, no noticeable scratches\u003cbr\u003e・Bezel: Minor scratches, no noticeable scratches\u003cbr\u003e・Case Back: Minor scratches, commemorative engraving, no noticeable scratches\u003cbr\u003e・Strap: (SEIKO made) Not original. Unused, new.\u003cbr\u003e・Hands\/Dial: Good condition, no signs of redial\u003c\/p\u003e\n\u003cp\u003e---\u003cbr\u003e### Important Notes\u003cbr\u003eCharacteristics of Vintage Items: This is a mechanical watch from the 1970s. Although it is currently operating very accurately, please understand that it is a vintage item based on our display standard (within 1-2 minutes daily rate). Regular maintenance is recommended for practical use.\u003cbr\u003eWater Resistance: Please treat it as non-water resistant. Assume that the original water resistance is no longer maintained and be extremely careful about water exposure and humidity.\u003cbr\u003eCalendar Operation: Due to the characteristics of the 56 series movement, absolutely avoid quick-setting the calendar between 8 PM and 4 AM (this may cause malfunction).\u003c\/p\u003e\n\u003cp\u003e---\u003cbr\u003e\u003c\/p\u003e","brand":"大山商店","offers":[{"title":"Default Title","offer_id":42521846677579,"sku":null,"price":149800.0,"currency_code":"JPY","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0280\/9914\/9899\/files\/20260530_095457_DSC_3339.jpg?v=1780104876","url":"https:\/\/008ma.com\/en\/products\/%e8%89%af%e5%93%81-seiko-%e3%82%bb%e3%82%a4%e3%82%b3%e3%83%bc-1971%e5%b9%b4-%e3%82%b0%e3%83%a9%e3%83%b3%e3%83%89%e3%82%bb%e3%82%a4%e3%82%b3%e3%83%bc-grand-seiko-hi-beat-%e3%83%87%e3%82%a4%e3%83%88-%e8%87%aa%e5%8b%95%e5%b7%bb-automatic-25%e7%9f%b3-ref-5645-7000-%e4%bf%9d%e3%81%82%e3%82%8a-oh%e6%b8%88","provider":"大山商店","version":"1.0","type":"link"}