Seiko Cal. 6631 - 252

The Seiko 6631-252 represents an important milestone in Seiko's 1977 lineup. Powered by the 6631 caliber with 26j jewels beating at 21,600 bph, it delivers a 40 hours power reserve. [seikata-wm-a23a4b5867d0]

Also known as: Sumo

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

39mm

Case Thickness

8.1mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

50m

Dial Color

Blue Sunburst

Jewels

26j

Frequency

21,600 bph

Power Reserve

40 hours

Year

1977

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