Seiko Cal. 4431 - 391

The 4431-391 is a sought-after Automatic piece from Seiko's golden era. Powered by the 4431 caliber with 36j jewels beating at 28,800 bph, it delivers a 64 hours power reserve. [seikata-wm-645db3759f68]

Also known as: Bullhead

Specifications

Movement

Automatic

Case Material

Titanium

Case Width

44mm

Case Thickness

13.4mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Inner Rotating

Water Resistance

60m

Dial Color

Cream

Jewels

36j

Frequency

28,800 bph

Power Reserve

64 hours

Year

1969

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