Seiko Cal. 6637 - 691

The Seiko 6637-691 represents an important milestone in Seiko's 1968 lineup. The Inner Rotating bezel and 39mm case give it a distinctive presence on the wrist. [seikata-wm-43529dd22d16]

Specifications

Movement

Spring Drive

Case Material

Stainless Steel

Case Width

39mm

Case Thickness

11.4mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

200m

Dial Color

Burgundy

Jewels

27j

Frequency

28,800 bph

Power Reserve

39 hours

Year

1968

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