Seiko Cal. 6631 - 351

Released in 1981, the Cal. 6631 with design code 351 was part of Seiko's domestic market collection. Powered by the 6631 caliber with 27j jewels beating at 28,800 bph, it delivers a 59 hours power reserve. [seikata-wm-719ed17fcf0a]

Also known as: Baby Tuna

Specifications

Movement

Kinetic

Case Material

Stainless Steel

Case Width

40mm

Case Thickness

13.8mm

Lug Width

19mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

130m

Dial Color

Green

Jewels

27j

Frequency

28,800 bph

Power Reserve

59 hours

Year

1981

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