Seiko Cal. 6631 - 737

This Hand-Winding model from 1968 features a 42mm Stainless Steel case. With its 20mm lug width and 14.4mm profile, it sits comfortably on most wrists. [seikata-wm-3b4e7af191b3]

Also known as: Bullhead, Golden Tuna

Specifications

Movement

Hand-Winding

Case Material

Stainless Steel

Case Width

42mm

Case Thickness

14.4mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

110m

Dial Color

White

Jewels

21j

Frequency

21,600 bph

Power Reserve

44 hours

Year

1968

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