Seiko Cal. 6640 - 318

Released in 1970, the Cal. 6640 with design code 318 was part of Seiko's domestic market collection. With its 21mm lug width and 8.3mm profile, it sits comfortably on most wrists. [seikata-wm-66da0917cf95]

Also known as: Goldfeather, Crown

Specifications

Movement

Quartz

Case Material

Stainless Steel

Case Width

34mm

Case Thickness

8.3mm

Lug Width

21mm

Crystal

Mineral

Bezel

Inner Rotating

Water Resistance

90m

Dial Color

Blue Sunburst

Jewels

21j

Frequency

21,600 bph

Power Reserve

47 hours

Year

1970

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