Seiko Cal. 5640 - 906

This Spring Drive model from 1974 features a 45mm Titanium case. It features a Black dial protected by a Hardlex crystal and offers 170m of water resistance. [seikata-wm-64d113b41fe2]

Also known as: Helmet

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

45mm

Case Thickness

15.9mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

170m

Dial Color

Black

Jewels

20j

Frequency

28,800 bph

Power Reserve

68 hours

Year

1974

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