Seiko Cal. 6637 - 591

The 6637-591 is a sought-after Spring Drive piece from Seiko's golden era. It features a Black dial protected by a Sapphire crystal and offers 60m of water resistance. [seikata-wm-248e9b169435]

Also known as: Sumo, Bellmatic

Specifications

Movement

Spring Drive

Case Material

Gold-Plated

Case Width

44mm

Case Thickness

8.1mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

60m

Dial Color

Black

Jewels

19j

Frequency

36,000 bph

Power Reserve

49 hours

Year

1982

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