Seiko Cal. 6631 - 659

This Spring Drive model from 1976 features a 36mm Hardlex-Coated Steel case. Powered by the 6631 caliber with 31j jewels beating at 21,600 bph, it delivers a 59 hours power reserve. [seikata-wm-2840caa8b23e]

Also known as: Sea Horse

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

36mm

Case Thickness

12.4mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

130m

Dial Color

Cream

Jewels

31j

Frequency

21,600 bph

Power Reserve

59 hours

Year

1976

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