Seiko Cal. 6637 - 281

The 6637-281 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 6637 caliber with 23j jewels beating at 28,800 bph, it delivers a 49 hours power reserve. [seikata-wm-4ab25d578011]

Also known as: Monster, Sportsmatic

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

37mm

Case Thickness

14.0mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

30m

Dial Color

Green

Jewels

23j

Frequency

28,800 bph

Power Reserve

49 hours

Year

1977

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