Seiko Cal. 5640 - 837

This Spring Drive model from 1979 features a 41mm PVD Black case. The Inner Rotating bezel and 41mm case give it a distinctive presence on the wrist. [seikata-wm-f9c6ce573511]

Also known as: Rally, World Timer

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

41mm

Case Thickness

15.9mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

180m

Dial Color

Cream

Jewels

28j

Frequency

36,000 bph

Power Reserve

57 hours

Year

1979

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