Designed with a stainless steel case and bracelet, this 41.0mm Grand Seiko Caliber 9R66, features the signature Grand Seiko clear ridges on the facets of the case and the diamond-cut hands and markers with red 24-hour hand on a black dial. Spring Drive, a unique Seiko movement that requires neither a battery nor an electric motor, makes it a completely self-contained system. Its power is derived from a mainspring, just like a mechanical watch, and its accuracy is controlled by the precise signal of a quartz oscillator. These watches are all accurate to ±10 seconds per month, a level that is higher than any other existing spring-wound watch in the world. Spring Drive movement allows for self and automatic winding capabilities and features 30 jewels, with accuracy +/- 1 second per day with over 72 hours power reserve. 100M Water Resistant. Men’s Grand Seiko Spring Drive GMT 41.0mm stainless steel case and bracelet with black dial.
Watches
Stainless Steel
41mm
Black
Date, Power Reserve, See Description, Time Zone
Automatic, See Description
Stainless Steel
What is the “Grand Seiko Standard?”
The Grand Seiko Standard is a Seiko-exclusive accuracy standard for mechanical watches which has been established to ensure superior performance of Grand Seiko mechanical watches irrespective of the differences in environmental conditions in which a watch is used. The Grand Seiko Standard differs from the other recognised chronometer standards in two important respects. While most accuracy standard testing is done for five positions at two temperatures, the Grand Seiko Standard tests six positions at three temperatures. This is because the Grand Seiko Standard seeks to replicate real world conditions.
How accurate is Grand Seiko?
The accuracy of Grand Seiko differs according to the mechanism and caliber of your watch.
QUARTZ : The annual accuracy is ±10 seconds when worn on the wrist within a normal temperature range (between 5 ºC and 35 ºC) for approximately 8 hours per day.
SPRING DRIVE : Average monthly loss / gain is ±15 seconds when worn on the wrist within a normal temperature range (between 5 ºC and 35 ºC）.
MECHANICAL : Accuracy of Grand Seiko mechanical watches when worn is specified within the target range of -1 to +10 seconds per day. To properly judge the accuracy under normal use conditions, check the mean value of gain / loss over a period of seven to ten days.
Where does Grand Seiko manufacture their watches?
As one of the very few fully integrated watch manufactures in the world, Grand Seiko possesses a mastery over the full breadth of the watchmaking process from the research and development of component materials to manufacture, assembly, adjustment, inspection and shipment.
— The Shizuku-Ishi Watch Studio produces world-class mechanical watches with highly accurate movements and exquisite exterior design
— The Shinshu Watch Studio drives innovative ideas and novel technologies behind the ultimate quartz watches and Seiko’s exclusive Spring Drive watches
Each of these pre-eminent watch studios plays a pivotal role in combining the cutting-edge technology and masterful craftsmanship necessary to reach the pinnacle of quality represented by Grand Seiko.
Click the button below to read more about Grand Seiko’s Shizuki-Ishi and Shinshu Watch Studios.
The brand celebrates the Japanese spirituality of time that is deeply inspired by nature and her seasons and brought to life by Takumi, the dedicated seekers of mastery.
It was the determination to excel that brought about the birth of Grand Seiko in 1960. During its development and ever since, the idea that drove the designers and engineers was that Grand Seiko should be the ‘ideal’ watch with standards of precision, durability and beauty that would lead the world.
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