Seiko Cal. 6631 - 394

This Hand-Winding model from 1966 features a 37mm PVD Black case. It features a Blue Sunburst dial protected by a Sapphire crystal and offers 120m of water resistance. [seikata-wm-97f09f77ca55]

Also known as: Golden Tuna

Specifications

Movement

Hand-Winding

Case Material

PVD Black

Case Width

37mm

Case Thickness

13.7mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

120m

Dial Color

Blue Sunburst

Jewels

18j

Frequency

21,600 bph

Power Reserve

54 hours

Year

1966

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