Seiko Cal. 5631 - 638

The 5631-638 is a sought-after Spring Drive piece from Seiko's golden era. It features a Blue Sunburst dial protected by a Acrylic crystal and offers 80m of water resistance. [seikata-wm-4f88e6d5b036]

Also known as: Bullhead, Rally

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

44mm

Case Thickness

8.0mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Fixed

Water Resistance

80m

Dial Color

Blue Sunburst

Jewels

28j

Frequency

28,800 bph

Power Reserve

43 hours

Year

1994

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