Seiko Cal. 5631 - 774

This Spring Drive model from 1987 features a 34mm Hardlex-Coated Steel case. With its 18mm lug width and 9.3mm profile, it sits comfortably on most wrists. [seikata-wm-6afe34c07b69]

Also known as: Baby Tuna

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

34mm

Case Thickness

9.3mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Fixed

Water Resistance

70m

Dial Color

Silver

Jewels

18j

Frequency

28,800 bph

Power Reserve

61 hours

Year

1987

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