Seiko Cal. 6631 - 639

The Seiko 6631-639 represents an important milestone in Seiko's 1997 lineup. With its 19mm lug width and 8.3mm profile, it sits comfortably on most wrists. [seikata-wm-6e7cd1801bbe]

Also known as: Monster, World Timer

Specifications

Movement

Automatic

Case Material

Titanium

Case Width

37mm

Case Thickness

8.3mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

110m

Dial Color

Champagne

Jewels

26j

Frequency

28,800 bph

Power Reserve

46 hours

Year

1997

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