Seiko Cal. 6640 - 422

The 6640-422 is a sought-after Quartz piece from Seiko's golden era. Powered by the 6640 caliber with 33j jewels beating at 28,800 bph, it delivers a 44 hours power reserve. [seikata-wm-82f2f444f8aa]

Also known as: Sumo, World Timer

Specifications

Movement

Quartz

Case Material

Hardlex-Coated Steel

Case Width

34mm

Case Thickness

12.6mm

Lug Width

19mm

Crystal

Acrylic

Bezel

Rotating

Water Resistance

190m

Dial Color

White

Jewels

33j

Frequency

28,800 bph

Power Reserve

44 hours

Year

1971

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