Seiko Cal. 6636 - 255

This Spring Drive model from 1975 features a 40mm Two-Tone case. With its 21mm lug width and 9.4mm profile, it sits comfortably on most wrists. [seikata-wm-9602e06c8bc4]

Also known as: Helmet, World Timer

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

40mm

Case Thickness

9.4mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Coin-Edge

Water Resistance

200m

Dial Color

Silver

Jewels

19j

Frequency

28,800 bph

Power Reserve

67 hours

Year

1975

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