Seiko Cal. 6637 - 644

The 6637-644 is a sought-after Automatic piece from Seiko's golden era. Powered by the 6637 caliber with 35j jewels beating at 36,000 bph, it delivers a 38 hours power reserve. [seikata-wm-a1bf5295e43a]

Also known as: Rally

Specifications

Movement

Automatic

Case Material

Hardlex-Coated Steel

Case Width

37mm

Case Thickness

12.4mm

Lug Width

19mm

Crystal

Mineral

Bezel

Rotating

Water Resistance

90m

Dial Color

Green

Jewels

35j

Frequency

36,000 bph

Power Reserve

38 hours

Year

1991

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