Seiko Cal. 6640 - 539

The Seiko 6640-539 represents an important milestone in Seiko's 1966 lineup. Powered by the 6640 caliber with 33j jewels beating at 28,800 bph, it delivers a 60 hours power reserve. [seikata-wm-2b629dbf04a6]

Also known as: Bellmatic, World Timer

Specifications

Movement

Kinetic

Case Material

PVD Black

Case Width

37mm

Case Thickness

11.2mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

180m

Dial Color

Blue Sunburst

Jewels

33j

Frequency

28,800 bph

Power Reserve

60 hours

Year

1966

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