Seiko Cal. 6631 - 147

The Seiko 6631-147 represents an important milestone in Seiko's 1975 lineup. Powered by the 6631 caliber with 23j jewels beating at 36,000 bph, it delivers a 47 hours power reserve. [seikata-wm-956eaad17ca2]

Also known as: Tuna, Navigator

Specifications

Movement

Automatic

Case Material

Hardlex-Coated Steel

Case Width

44mm

Case Thickness

13.1mm

Lug Width

19mm

Crystal

Mineral

Bezel

Fixed

Water Resistance

180m

Dial Color

Burgundy

Jewels

23j

Frequency

36,000 bph

Power Reserve

47 hours

Year

1975

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