Released in 1974, the Cal. 6620 with design code 399 was part of Seiko's domestic market collection. Powered by the 6620 caliber with 23j jewels beating at 36,000 bph, it delivers a 48 hours power reserve. [seikata-wm-df3f2d4a4e20]
Also known as: Tuna, Baby Tuna
