Seiko Cal. 5666 - 940

The 5666-940 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 5666 caliber with 23j jewels beating at 28,800 bph, it delivers a 58 hours power reserve. [seikata-wm-22e1e7c7af65]

Also known as: Monster, Baby Tuna

Specifications

Movement

Spring Drive

Case Material

Gold-Plated

Case Width

38mm

Case Thickness

13.6mm

Lug Width

22mm

Crystal

Hardlex

Bezel

Rotating

Water Resistance

100m

Dial Color

Burgundy

Jewels

23j

Frequency

28,800 bph

Power Reserve

58 hours

Year

1990

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