Grand Seiko 57GS 5722-9991 GS Medal
As the second Grand Seiko model, 57GS was the first GS having the calendar function, a.k.a. self dater. It was very popular and Seiko decided to continue its production until 1968 (5 years in total). The long production period created many variations for 57GS, such as 43999, 5722-9990 and 5722-9991. 57GS was reissued by Seiko as limited edition in 2010s, but with 9F series quartz movements.
Year: May 1967
Diameter (excluding the crown): 37mm
Caliber: Original Cal.5722B manual movement
Accessories: Watch only
Service History: Unknown