Seiko Cal. 6637 - 691

The 6637-691 is a sought-after Quartz piece from Seiko's golden era. Powered by the 6637 caliber with 28j jewels beating at 36,000 bph, it delivers a 41 hours power reserve. [seikata-wm-b98f9506cfb1]

Also known as: Sumo, Golden Tuna

Specifications

Movement

Quartz

Case Material

Gold-Plated

Case Width

43mm

Case Thickness

10.0mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Rotating

Water Resistance

60m

Dial Color

Champagne

Jewels

28j

Frequency

36,000 bph

Power Reserve

41 hours

Year

1980

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