Seiko Cal. 6637 - 561

The 6637-561 is a sought-after Automatic piece from Seiko's golden era. Powered by the 6637 caliber with 27j jewels beating at 36,000 bph, it delivers a 46 hours power reserve. [seikata-wm-8817a7c33d19]

Also known as: Helmet

Specifications

Movement

Automatic

Case Material

Hardlex-Coated Steel

Case Width

36mm

Case Thickness

12.6mm

Lug Width

18mm

Crystal

Mineral

Bezel

Inner Rotating

Water Resistance

190m

Dial Color

Green

Jewels

27j

Frequency

36,000 bph

Power Reserve

46 hours

Year

1977

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