Seiko Cal. 6638 - 735

This Spring Drive model from 1978 features a 39mm Two-Tone case. The Fixed bezel and 39mm case give it a distinctive presence on the wrist. [seikata-wm-69569404e879]

Also known as: Sumo

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

39mm

Case Thickness

10.0mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

70m

Dial Color

Champagne

Jewels

29j

Frequency

28,800 bph

Power Reserve

71 hours

Year

1978

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