Seiko Cal. 5631 - 392

The 5631-392 is a sought-after Spring Drive piece from Seiko's golden era. With its 18mm lug width and 13.4mm profile, it sits comfortably on most wrists. [seikata-wm-d6fde2e485ee]

Also known as: Bellmatic, Baby Tuna

Specifications

Movement

Spring Drive

Case Material

Two-Tone

Case Width

40mm

Case Thickness

13.4mm

Lug Width

18mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

60m

Dial Color

Cream

Jewels

26j

Frequency

36,000 bph

Power Reserve

60 hours

Year

1974

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