Seiko Cal. 6640 - 550

The Seiko 6640-550 represents an important milestone in Seiko's 1975 lineup. It features a Green dial protected by a Hardlex crystal and offers 50m of water resistance. [seikata-wm-47e939332b8f]

Also known as: Samurai

Specifications

Movement

Automatic

Case Material

Hardlex-Coated Steel

Case Width

39mm

Case Thickness

9.0mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

50m

Dial Color

Green

Jewels

22j

Frequency

21,600 bph

Power Reserve

38 hours

Year

1975

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