Seiko Cal. 5644 - 638

The Seiko 5644-638 represents an important milestone in Seiko's 1970 lineup. With its 21mm lug width and 10.7mm profile, it sits comfortably on most wrists. [seikata-wm-09396756cf3f]

Also known as: Silverwave

Specifications

Movement

Quartz

Case Material

Hardlex-Coated Steel

Case Width

43mm

Case Thickness

10.7mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

140m

Dial Color

Blue Sunburst

Jewels

18j

Frequency

28,800 bph

Power Reserve

46 hours

Year

1970

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