Seiko Cal. 4421 - 728

This Spring Drive model from 1971 features a 45mm Titanium case. The Fixed bezel and 45mm case give it a distinctive presence on the wrist. [seikata-wm-c7792b74a565]

Also known as: Sumo

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

45mm

Case Thickness

10.8mm

Lug Width

21mm

Crystal

Mineral

Bezel

Fixed

Water Resistance

90m

Dial Color

White

Jewels

23j

Frequency

21,600 bph

Power Reserve

60 hours

Year

1971

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