Seiko Cal. 6640 - 285

Released in 1972, the Cal. 6640 with design code 285 was part of Seiko's domestic market collection. The Rotating bezel and 37mm case give it a distinctive presence on the wrist. [seikata-wm-34691ead00ff]

Also known as: Tuna

Specifications

Movement

Quartz

Case Material

Gold-Plated

Case Width

37mm

Case Thickness

14.7mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

180m

Dial Color

Black

Jewels

29j

Frequency

21,600 bph

Power Reserve

44 hours

Year

1972

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