Seiko Cal. 6639 - 915

The Seiko 6639-915 represents an important milestone in Seiko's 1966 lineup. Powered by the 6639 caliber with 23j jewels beating at 21,600 bph, it delivers a 71 hours power reserve. [seikata-wm-9ca82474f87d]

Also known as: Sumo, Baby Tuna

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

36mm

Case Thickness

13.7mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Fixed

Water Resistance

30m

Dial Color

Navy

Jewels

23j

Frequency

21,600 bph

Power Reserve

71 hours

Year

1966

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