Seiko Cal. 6331 - 990

The Seiko 6331-990 represents an important milestone in Seiko's 1981 lineup. Powered by the 6331 caliber with 26j jewels beating at 28,800 bph, it delivers a 72 hours power reserve. [seikata-wm-d0fdb93fb769]

Also known as: Sportsmatic

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

41mm

Case Thickness

12.3mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

90m

Dial Color

Cream

Jewels

26j

Frequency

28,800 bph

Power Reserve

72 hours

Year

1981

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