Seiko Cal. 4540 - 307

This Spring Drive model from 1971 features a 37mm PVD Black case. With its 20mm lug width and 15.6mm profile, it sits comfortably on most wrists. [seikata-wm-c18883d66cd8]

Also known as: World Timer

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

37mm

Case Thickness

15.6mm

Lug Width

20mm

Crystal

Mineral

Bezel

Fixed

Water Resistance

190m

Dial Color

Blue Sunburst

Jewels

21j

Frequency

28,800 bph

Power Reserve

62 hours

Year

1971

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