Seiko Cal. 5641 - 904

The 5641-904 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 5641 caliber with 21j jewels beating at 21,600 bph, it delivers a 71 hours power reserve. [seikata-wm-42b8614982b5]

Also known as: Sumo

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

36mm

Case Thickness

10.2mm

Lug Width

20mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

60m

Dial Color

Green

Jewels

21j

Frequency

21,600 bph

Power Reserve

71 hours

Year

1969

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