Seiko Cal. 6640 - 688

The 6640-688 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 6640 caliber with 31j jewels beating at 21,600 bph, it delivers a 38 hours power reserve. [seikata-wm-0c7bce1b2974]

Also known as: Samurai

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

46mm

Case Thickness

10.3mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

120m

Dial Color

Cream

Jewels

31j

Frequency

21,600 bph

Power Reserve

38 hours

Year

1972

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