Seiko Cal. 6640 - 778

The Seiko 6640-778 represents an important milestone in Seiko's 1974 lineup. It features a Black dial protected by a Hardlex crystal and offers 90m of water resistance. [seikata-wm-de594620304f]

Specifications

Movement

Hand-Winding

Case Material

Gold-Plated

Case Width

43mm

Case Thickness

12.3mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

90m

Dial Color

Black

Jewels

17j

Frequency

36,000 bph

Power Reserve

48 hours

Year

1974

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