Released in 1969, the Cal. 6638 with design code 270 was part of Seiko's domestic market collection. Powered by the 6638 caliber with 31j jewels beating at 21,600 bph, it delivers a 50 hours power reserve. [seikata-wm-a1c8694e4c5c]
Also known as: Sportsmatic, Arnie
