Seiko Cal. 6640 - 590

The Seiko 6640-590 represents an important milestone in Seiko's 1976 lineup. It features a Navy dial protected by a Hardlex crystal and offers 170m of water resistance. [seikata-wm-12112ba5bc3c]

Also known as: Sumo

Specifications

Movement

Quartz

Case Material

Stainless Steel

Case Width

35mm

Case Thickness

14.3mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

170m

Dial Color

Navy

Jewels

31j

Frequency

21,600 bph

Power Reserve

63 hours

Year

1976

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