Seiko Cal. 5638 - 645

This Hand-Winding model from 1991 features a 41mm Titanium case. It features a Green dial protected by a Sapphire crystal and offers 100m of water resistance. [seikata-wm-cdf612f65d1d]

Also known as: Sumo

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

41mm

Case Thickness

12.2mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

100m

Dial Color

Green

Jewels

28j

Frequency

36,000 bph

Power Reserve

38 hours

Year

1991

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