Seiko Cal. 6640 - 639

The Seiko 6640-639 represents an important milestone in Seiko's 1981 lineup. The Inner Rotating bezel and 34mm case give it a distinctive presence on the wrist. [seikata-wm-0f00f72f3781]

Specifications

Movement

Kinetic

Case Material

Titanium

Case Width

34mm

Case Thickness

14.9mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

50m

Dial Color

Blue Sunburst

Jewels

36j

Frequency

36,000 bph

Power Reserve

64 hours

Year

1981

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