Seiko Cal. 4520 - 428

The 4520-428 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 4520 caliber with 20j jewels beating at 36,000 bph, it delivers a 49 hours power reserve. [seikata-wm-2aadd0143e8a]

Also known as: Monster, UFO

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

34mm

Case Thickness

11.2mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

140m

Dial Color

Blue Sunburst

Jewels

20j

Frequency

36,000 bph

Power Reserve

49 hours

Year

1972

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