Seiko Cal. 6636 - 763

This Spring Drive model from 1966 features a 43mm Titanium case. Powered by the 6636 caliber with 36j jewels beating at 28,800 bph, it delivers a 58 hours power reserve. [seikata-wm-bf07c0f87fe7]

Also known as: Helmet, World Timer

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

43mm

Case Thickness

11.7mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Coin-Edge

Water Resistance

40m

Dial Color

Silver

Jewels

36j

Frequency

28,800 bph

Power Reserve

58 hours

Year

1966

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