Seiko Cal. 6638 - 240

The 6638-240 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 6638 caliber with 31j jewels beating at 36,000 bph, it delivers a 69 hours power reserve. [seikata-wm-eb381a3642d2]

Also known as: Baby Tuna, Emperor

Specifications

Movement

Spring Drive

Case Material

Stainless Steel

Case Width

38mm

Case Thickness

8.9mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

60m

Dial Color

Blue Sunburst

Jewels

31j

Frequency

36,000 bph

Power Reserve

69 hours

Year

1976

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