Seiko Cal. 5631 - 439

This Automatic model from 1970 features a 41mm PVD Black case. Powered by the 5631 caliber with 35j jewels beating at 36,000 bph, it delivers a 70 hours power reserve. [seikata-wm-c5aea32282d5]

Also known as: Golden Tuna

Specifications

Movement

Automatic

Case Material

PVD Black

Case Width

41mm

Case Thickness

13.1mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

140m

Dial Color

Silver

Jewels

35j

Frequency

36,000 bph

Power Reserve

70 hours

Year

1970

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