Seiko Cal. 4428 - 906

The 4428-906 is a sought-after Spring Drive piece from Seiko's golden era. With its 21mm lug width and 15.7mm profile, it sits comfortably on most wrists. [seikata-wm-2b7ac0a8f720]

Also known as: Sumo, Sportsmatic

Specifications

Movement

Spring Drive

Case Material

Gold-Plated

Case Width

43mm

Case Thickness

15.7mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

120m

Dial Color

Champagne

Jewels

28j

Frequency

36,000 bph

Power Reserve

65 hours

Year

1965

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