Seiko Cal. 6638 - 378

The Seiko 6638-378 represents an important milestone in Seiko's 1972 lineup. With its 20mm lug width and 14.6mm profile, it sits comfortably on most wrists. [seikata-wm-eef13aff7c2f]

Also known as: Monster, Rally

Specifications

Movement

Automatic

Case Material

Titanium

Case Width

44mm

Case Thickness

14.6mm

Lug Width

20mm

Crystal

Mineral

Bezel

Inner Rotating

Water Resistance

40m

Dial Color

Champagne

Jewels

22j

Frequency

28,800 bph

Power Reserve

47 hours

Year

1972

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