Seiko Cal. 6640 - 510

Released in 1968, the Cal. 6640 with design code 510 was part of Seiko's domestic market collection. It features a Blue Sunburst dial protected by a Acrylic crystal and offers 120m of water resistance. [seikata-wm-2da6e434e408]

Also known as: Emperor

Specifications

Movement

Quartz

Case Material

Hardlex-Coated Steel

Case Width

43mm

Case Thickness

9.8mm

Lug Width

22mm

Crystal

Acrylic

Bezel

Rotating

Water Resistance

120m

Dial Color

Blue Sunburst

Jewels

33j

Frequency

21,600 bph

Power Reserve

71 hours

Year

1968

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