Grand Seiko 57GS complete guide
The 57GS, developed by Suwa Seikosha, is the first family of Grand Seiko watches, introduced in late 1960 with the Grand Seiko Chronometer, commonly known nowadays as the Grand Seiko First. The Grand Seiko 57GS family consists of the following movements: Caliber 3180, later renamed 5720A, was accurate to within +12 to -3 seconds a day, running at 18,000 bph with 45 hours of power reserve Caliber 430, later renamed …