Seiko Cal. 5643 - 740

The Seiko 5643-740 represents an important milestone in Seiko's 1969 lineup. Powered by the 5643 caliber with 24j jewels beating at 28,800 bph, it delivers a 49 hours power reserve. [seikata-wm-4f02996ffb08]

Also known as: Helmet, Golden Tuna

Specifications

Movement

Spring Drive

Case Material

Gold-Plated

Case Width

35mm

Case Thickness

9.1mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

130m

Dial Color

Blue Sunburst

Jewels

24j

Frequency

28,800 bph

Power Reserve

49 hours

Year

1969

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