{"product_id":"seiko-sbga437-grand-seiko-heritage-collection-spring-drive-automatic-37mm-stainless-steel-sapphire-crystal-elegant","title":"SEIKO SBGA437 Grand Seiko Heritage Collection Spring Drive Automatic 37mm Stainless Steel Sapphire Crystal Elegant","description":"```html\n\u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"font-weight:800;padding:8px;background:#d9d9d9;\"\u003eProduct Highlights\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"padding:8px;\"\u003eA beautiful shining \"Thick Silver Radiant\" dial from Grand Seiko\nShinshu, where Grand Seiko's workshop is located, was once a major production area for silk. The dial, named \"Thick Silver Radiant,\" pays homage to this manufacturing region. The glossy dial features a delicate radiant pattern that looks as if it were drawn with silk, reflecting a commitment to its roots. This intricate pattern can only be created with soft silver, achieved through a special technique applied to silver plating. The movement housed in this watch is Grand Seiko's unique Spring Drive. The second hand glides silently across the dial, a characteristic feature of the Spring Drive. The maximum power reserve lasts approximately 72 hours (about 3 days), and the remaining duration can be checked on the power reserve display located at the bottom left of the dial.\nGrand Seiko\nManufacture\nGrand Seiko is a true manufacture that handles everything in-house, from movement development to design, manufacturing, assembly, adjustment, inspection, and shipping. In an environment where each component can be researched and developed from the material level, cutting-edge technology is fused with the highest level of craftsmanship. Two workshops nurtured by rich nature produce three movements.\nThe Spirit of Takumi\nThe attitude of Grand Seiko's artisans who endlessly pursue the essence of time. This is akin to the way of \"Do\" seen in traditional Japanese martial arts, tea ceremony, and flower arrangement. By honing their skills and deepening their spirituality, this path becomes sharper and opens up new realms. To embody the ever-changing passage of time within a watch, they strive for high precision, visibility, and aesthetic beauty. Creating a true ideal watch that shines eternally across generations. The challenge of the artisans knows no end.\nLight and Shadow\nThe Japanese delicately perceive, savor, and cherish the countless expressions created by light and shadow as time flows. The design is characterized by sharp, distortion-free flat surfaces and straight lines. The mirror finish is meticulously polished with exceptional craftsmanship. The multi-faceted cut indices and thick hands are designed to create beautiful expressions even as light changes with time and place, shining brilliantly while maintaining high visibility.\nSpecifications\nExterior: Stainless Steel\nGlass Material: Dual Curve Sapphire\nCoating: Anti-reflective coating on the inner surface\nCase Size: Width 40mm   Height 46.6mm   Thickness 12.3mm\nWrist Size (Maximum): 203mm\nClasp: One-push three-fold type\nDrive Type: Spring Drive\nPower Reserve: Approximately 72 hours (about 3 days) at maximum winding\nAccuracy: Average monthly difference ±15 seconds (equivalent to daily difference ±1 second)\nWater Resistance: Daily life water-resistant (10 ATM)\nMagnetic Resistance: Yes\nWeight: 157.0 g\nOthers:\n・Screw back\n・Screw lock type crown\n・Calendar (date) function\n・Number of jewels: 30\n・Second hand stop function\n・Power reserve display function\n・Back cover with lion emblem\nGrand Seiko continues to pursue the essence of watches as a timepiece to walk through life with.\n■ 9R Spring Drive\nThe Spring Drive is a unique drive mechanism from Seiko that uses a mainspring, which is the power source for mechanical watches, while controlling accuracy through precise signals from a quartz crystal oscillator, which is the control system for quartz watches. The Spring Drive, equipped with a hybrid engine that incorporates the best features of both mechanical and quartz watches, can be described as a \"mechanical watch with high precision\" and also as a \"quartz watch that does not use batteries or motors.\"\n◆ A Hybrid Mechanism of Mechanics and Quartz\nThe major elements in the mechanism that makes the watch move are \"power\" and \"control system.\"\n・\"Power\" is the force that drives the watch.\n・\"Control system\" is the mechanism that controls the movement of the watch.\nThe Spring Drive is a hybrid movement that adopts \"power: high torque\" from mechanical watches and \"control system: high precision through IC control\" from quartz watches.\n\"Power\" is the \"mainspring\" used in mechanical watches.\nThe power of the Spring Drive comes from the \"mainspring\" used in mechanical watches, a self-contained drive system that does not rely on batteries or motors. When the crown is wound, the mainspring is wound up, and the force trying to unwind the mainspring is transmitted to the gears, moving the hands attached to the gears. The Spring Drive can rotate the thick and heavy hands characteristic of Grand Seiko because it utilizes a high-torque mainspring (rather than a motor).\nThe \"control system\" is the \"Tri-Synchro Regulator.\"\nThe control system of the Spring Drive is a unique speed control mechanism that uses electrical signals from the IC and quartz oscillator used in quartz watches. \nImagine a toy powered by a mainspring. If the unwinding speed is not adjusted, the mainspring will unwind all at once, and the toy will stop. Therefore, a mechanism is needed to maintain a constant unwinding speed. The \"Tri-Synchro Regulator,\" developed for the Spring Drive, fulfills this role.\nThe TRI in Tri-Synchro Regulator (TRI【3】-SYNCHRO【synchronize】 REGULATOR【speed controller】) refers to:\n① Mechanical force ② Electrical signal ③ Magnetic force\nThese three interact to create the precise movement of the second hand.\n1. Mechanical force (power: mainspring)\nGenerating electricity with the unwinding force of the mainspring.\nFor example, a bicycle light uses the power of the rotating tire to emit light. The Spring Drive generates power using the same principle, with the rotor and coil wound stator acting as the generator. The rotor generates a small amount of electrical energy by rotating 8 times per second.\n2. Electrical signal (precise signal: IC and quartz oscillator)\nThe quartz oscillator emits a precise signal.\nUsing a small amount of electricity, the quartz oscillator and IC are activated. When power is transmitted to the quartz oscillator, it sends a precise signal of 32,768Hz per second to the IC, equivalent to quartz.\n3. Magnetic force (brake: rotor and stator)\nApplying a brake to the rotor to control speed.\nThe IC compares the precise signal from the quartz oscillator with the rotor's rotation speed, intermittently applying magnetic brakes to prevent the rotor from spinning too fast, maintaining a constant speed. By keeping the rotor's rotation constant, controlled movements are transmitted in sequence from the rotor to the gears and hands, accurately marking the time.\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"font-weight:800;padding:8px;background:#d9d9d9;\"\u003eSpecifications\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eDrive Type\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eMechanical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eRadio Wave Automatic Correction Function\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eNone\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eDisplay Type\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eAnalog\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eCase\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eBezel SS, Body SS, Back Cover SS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eGlass\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eDual Curve Sapphire Glass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eBand Material\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eMetal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eBand (Adjustable)\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eScrew type\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eAccuracy\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eAverage monthly difference ±15 seconds (equivalent to daily difference ±1 second)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eSpecification 1\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eNumber of jewels: 30, Power reserve display function, Second hand stop function, Calendar (date) function\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eSpecification 2\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003eBack cover with lion emblem, Screw back, Screw lock type crown\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border-bottom:1px solid #5d5d5d;font-weight:600;padding:6px 10px;width:35%;\"\u003eList Price\u003c\/td\u003e\n\u003ctd style=\"border-bottom:1px solid #ccc;padding:6px 10px;\"\u003e¥682,000 JPY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n```","brand":"SEIKO","offers":[{"title":"Default Title","offer_id":47586197143636,"sku":"SBGA437","price":544521.0,"currency_code":"JPY","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0284\/7401\/5828\/files\/SBGA437_4.jpg?v=1787850637","url":"https:\/\/www.ippojapanwatch.com\/products\/seiko-sbga437-grand-seiko-heritage-collection-spring-drive-automatic-37mm-stainless-steel-sapphire-crystal-elegant","provider":"IPPO JAPAN WATCH ","version":"1.0","type":"link"}