Seiko Cal. 5640 - 154

The Seiko 5640-154 represents an important milestone in Seiko's 1988 lineup. Powered by the 5640 caliber with 20j jewels beating at 36,000 bph, it delivers a 59 hours power reserve. [seikata-wm-f15d15870149]

Also known as: Helmet, Navigator

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

34mm

Case Thickness

11.7mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

100m

Dial Color

Green

Jewels

20j

Frequency

36,000 bph

Power Reserve

59 hours

Year

1988

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