Seiko Cal. 6631 - 723

This Quartz model from 1971 features a 36mm Hardlex-Coated Steel case. With its 21mm lug width and 9.4mm profile, it sits comfortably on most wrists. [seikata-wm-d5df3ab95c6a]

Also known as: Bullhead, Flighty

Specifications

Movement

Quartz

Case Material

Hardlex-Coated Steel

Case Width

36mm

Case Thickness

9.4mm

Lug Width

21mm

Crystal

Mineral

Bezel

Bidirectional

Water Resistance

30m

Dial Color

Black

Jewels

32j

Frequency

36,000 bph

Power Reserve

39 hours

Year

1971

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