Seiko Cal. 5631 - 917

The Seiko 5631-917 represents an important milestone in Seiko's 1977 lineup. With its 18mm lug width and 8.3mm profile, it sits comfortably on most wrists. [seikata-wm-7e3696cf6aa6]

Also known as: Sportsmatic

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

45mm

Case Thickness

8.3mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Fixed

Water Resistance

170m

Dial Color

Blue Sunburst

Jewels

26j

Frequency

36,000 bph

Power Reserve

68 hours

Year

1977

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