Seiko Cal. 4431 - 640

This Hand-Winding model from 1973 features a 40mm Titanium case. Powered by the 4431 caliber with 31j jewels beating at 28,800 bph, it delivers a 54 hours power reserve. [seikata-wm-cc19f9a6b7e7]

Also known as: Panda, Golden Tuna

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

40mm

Case Thickness

8.8mm

Lug Width

20mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

30m

Dial Color

Navy

Jewels

31j

Frequency

28,800 bph

Power Reserve

54 hours

Year

1973

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