Seiko Cal. 6640 - 560

The Seiko 6640-560 represents an important milestone in Seiko's 1983 lineup. The Inner Rotating bezel and 35mm case give it a distinctive presence on the wrist. [seikata-wm-4e1e185ed75d]

Also known as: Tuna

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

35mm

Case Thickness

9.3mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

150m

Dial Color

Black

Jewels

29j

Frequency

28,800 bph

Power Reserve

40 hours

Year

1983

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