Seiko Cal. 5665 - 640

This Spring Drive model from 1967 features a 45mm Hardlex-Coated Steel case. With its 19mm lug width and 11.3mm profile, it sits comfortably on most wrists. [seikata-wm-c9d7341f42c8]

Also known as: Helmet

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

45mm

Case Thickness

11.3mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

50m

Dial Color

Silver

Jewels

35j

Frequency

21,600 bph

Power Reserve

60 hours

Year

1967

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