Seiko Cal. 6657 - 645

The Seiko 6657-645 represents an important milestone in Seiko's 1972 lineup. It features a Black dial protected by a Hardlex crystal and offers 180m of water resistance. [seikata-wm-9d509657ce55]

Also known as: Helmet, Emperor

Specifications

Movement

Automatic

Case Material

Stainless Steel

Case Width

37mm

Case Thickness

12.3mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

180m

Dial Color

Black

Jewels

31j

Frequency

36,000 bph

Power Reserve

55 hours

Year

1972

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