Seiko Cal. 6640 - 284

This Spring Drive model from 1979 features a 37mm PVD Black case. With its 19mm lug width and 15.9mm profile, it sits comfortably on most wrists. [seikata-wm-3f0e7f311f22]

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

37mm

Case Thickness

15.9mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

130m

Dial Color

Navy

Jewels

22j

Frequency

28,800 bph

Power Reserve

54 hours

Year

1979

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