Seiko Cal. 6631 - 990

The Seiko 6631-990 represents an important milestone in Seiko's 1986 lineup. The Coin-Edge bezel and 41mm case give it a distinctive presence on the wrist. [seikata-wm-65cfaf663cef]

Also known as: Turtle, Flighty

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

41mm

Case Thickness

9.0mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

180m

Dial Color

Champagne

Jewels

30j

Frequency

21,600 bph

Power Reserve

70 hours

Year

1986

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