Seiko Cal. 6631 - 147

This Spring Drive model from 1987 features a 38mm PVD Black case. The Bidirectional bezel and 38mm case give it a distinctive presence on the wrist. [seikata-wm-c3fd770b155b]

Also known as: Baby Tuna

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

38mm

Case Thickness

8.8mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Bidirectional

Water Resistance

160m

Dial Color

Green

Jewels

23j

Frequency

28,800 bph

Power Reserve

38 hours

Year

1987

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