Seiko Cal. 6637 - 838

This Spring Drive model from 1977 features a 42mm PVD Black case. Powered by the 6637 caliber with 20j jewels beating at 21,600 bph, it delivers a 61 hours power reserve. [seikata-wm-4d846a6fb14f]

Also known as: Helmet, Goldfeather

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

42mm

Case Thickness

13.0mm

Lug Width

20mm

Crystal

Acrylic

Bezel

Fixed

Water Resistance

60m

Dial Color

Silver

Jewels

20j

Frequency

21,600 bph

Power Reserve

61 hours

Year

1977

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