Seiko Cal. 6639 - 748

This Quartz model from 1978 features a 41mm Titanium case. With its 21mm lug width and 12.7mm profile, it sits comfortably on most wrists. [seikata-wm-a237c9ca7e59]

Also known as: Sumo

Specifications

Movement

Quartz

Case Material

Titanium

Case Width

41mm

Case Thickness

12.7mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

60m

Dial Color

Green

Jewels

25j

Frequency

36,000 bph

Power Reserve

51 hours

Year

1978

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