Seiko Cal. 6640 - 634

This Quartz model from 1983 features a 36mm Titanium case. Powered by the 6640 caliber with 33j jewels beating at 21,600 bph, it delivers a 54 hours power reserve. [seikata-wm-506baad9502e]

Also known as: Tuna, Sportsmatic

Specifications

Movement

Quartz

Case Material

Titanium

Case Width

36mm

Case Thickness

8.3mm

Lug Width

20mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

30m

Dial Color

Navy

Jewels

33j

Frequency

21,600 bph

Power Reserve

54 hours

Year

1983

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