Seiko Cal. 6631 - 930

The Seiko 6631-930 represents an important milestone in Seiko's 1975 lineup. Powered by the 6631 caliber with 34j jewels beating at 28,800 bph, it delivers a 41 hours power reserve. [seikata-wm-8509344244dd]

Also known as: Tuna

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

44mm

Case Thickness

13.2mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

120m

Dial Color

Blue Sunburst

Jewels

34j

Frequency

28,800 bph

Power Reserve

41 hours

Year

1975

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