Seiko Cal. 6637 - 935

This Hand-Winding model from 1978 features a 35mm Two-Tone case. With its 18mm lug width and 11.0mm profile, it sits comfortably on most wrists. [seikata-wm-4159c43078ed]

Also known as: Sumo, Helmet

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

35mm

Case Thickness

11.0mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

200m

Dial Color

Black

Jewels

17j

Frequency

28,800 bph

Power Reserve

40 hours

Year

1978

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