Seiko Cal. 6640 - 657

The Seiko 6640-657 represents an important milestone in Seiko's 1984 lineup. It features a Burgundy dial protected by a Hardlex crystal and offers 30m of water resistance. [seikata-wm-9d72b3afd600]

Also known as: Navigator

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

46mm

Case Thickness

9.0mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

30m

Dial Color

Burgundy

Jewels

21j

Frequency

21,600 bph

Power Reserve

40 hours

Year

1984

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