Seiko Cal. 6631 - 173

This Spring Drive model from 1989 features a 35mm Hardlex-Coated Steel case. With its 18mm lug width and 14.0mm profile, it sits comfortably on most wrists. [seikata-wm-df97c5852d0e]

Also known as: Bullhead, Bellmatic

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

35mm

Case Thickness

14.0mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

40m

Dial Color

Blue Sunburst

Jewels

20j

Frequency

36,000 bph

Power Reserve

53 hours

Year

1989

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