Seiko Cal. 5640 - 873

The Seiko 5640-873 represents an important milestone in Seiko's 1978 lineup. Powered by the 5640 caliber with 18j jewels beating at 36,000 bph, it delivers a 70 hours power reserve. [seikata-wm-f6f668c325fa]

Also known as: Sumo, Baby Tuna

Specifications

Movement

Kinetic

Case Material

Stainless Steel

Case Width

38mm

Case Thickness

15.5mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Bidirectional

Water Resistance

120m

Dial Color

Green

Jewels

18j

Frequency

36,000 bph

Power Reserve

70 hours

Year

1978

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