Seiko Cal. 6644 - 591

The Seiko 6644-591 represents an important milestone in Seiko's 1981 lineup. The Bidirectional bezel and 42mm case give it a distinctive presence on the wrist. [seikata-wm-d2e8278bd0e8]

Also known as: Helmet, UFO

Specifications

Movement

Kinetic

Case Material

Stainless Steel

Case Width

42mm

Case Thickness

10.7mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Bidirectional

Water Resistance

100m

Dial Color

Green

Jewels

32j

Frequency

28,800 bph

Power Reserve

66 hours

Year

1981

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