Seiko Cal. 6638 - 610

The Seiko 6638-610 represents an important milestone in Seiko's 1975 lineup. Powered by the 6638 caliber with 29j jewels beating at 21,600 bph, it delivers a 61 hours power reserve. [seikata-wm-28567dcf7eed]

Also known as: UFO, Golden Tuna

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

34mm

Case Thickness

14.8mm

Lug Width

20mm

Crystal

Acrylic

Bezel

Bidirectional

Water Resistance

180m

Dial Color

Blue Sunburst

Jewels

29j

Frequency

21,600 bph

Power Reserve

61 hours

Year

1975

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