Seiko Cal. 4420 - 423

This Spring Drive model from 1976 features a 42mm PVD Black case. Powered by the 4420 caliber with 18j jewels beating at 21,600 bph, it delivers a 56 hours power reserve. [seikata-wm-e42ba4f32bc9]

Also known as: UFO, World Timer

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

42mm

Case Thickness

15.1mm

Lug Width

22mm

Crystal

Mineral

Bezel

Coin-Edge

Water Resistance

120m

Dial Color

Green

Jewels

18j

Frequency

21,600 bph

Power Reserve

56 hours

Year

1976

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