Seiko Cal. 6640 - 231

The 6640-231 is a sought-after Automatic piece from Seiko's golden era. Powered by the 6640 caliber with 25j jewels beating at 28,800 bph, it delivers a 71 hours power reserve. [seikata-wm-1163114d27d6]

Also known as: Golden Tuna

Specifications

Movement

Automatic

Case Material

Titanium

Case Width

44mm

Case Thickness

10.8mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

40m

Dial Color

White

Jewels

25j

Frequency

28,800 bph

Power Reserve

71 hours

Year

1984

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