Seiko Cal. 6399 - 631

The 6399-631 is a sought-after Spring Drive piece from Seiko's golden era. With its 18mm lug width and 9.1mm profile, it sits comfortably on most wrists. [seikata-wm-4ab4fd7ad38e]

Also known as: Sumo, Bullhead

Specifications

Movement

Spring Drive

Case Material

Stainless Steel

Case Width

39mm

Case Thickness

9.1mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

190m

Dial Color

Green

Jewels

28j

Frequency

28,800 bph

Power Reserve

54 hours

Year

1966

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