Seiko Cal. 5631 - 645

This Automatic model from 1979 features a 37mm Titanium case. Powered by the 5631 caliber with 36j jewels beating at 28,800 bph, it delivers a 71 hours power reserve. [seikata-wm-060397f57cb6]

Also known as: UFO, Bellmatic

Specifications

Movement

Automatic

Case Material

Titanium

Case Width

37mm

Case Thickness

14.4mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

170m

Dial Color

Burgundy

Jewels

36j

Frequency

28,800 bph

Power Reserve

71 hours

Year

1979

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