Seiko Cal. 6637 - 812

The 6637-812 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 6637 caliber with 25j jewels beating at 36,000 bph, it delivers a 55 hours power reserve. [seikata-wm-ef8fc1d3345b]

Also known as: Turtle, Shogun

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

39mm

Case Thickness

15.5mm

Lug Width

21mm

Crystal

Acrylic

Bezel

Fixed

Water Resistance

150m

Dial Color

Navy

Jewels

25j

Frequency

36,000 bph

Power Reserve

55 hours

Year

1969

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