Seiko Cal. 6641 - 378

This Spring Drive model from 1976 features a 37mm Hardlex-Coated Steel case. Powered by the 6641 caliber with 29j jewels beating at 28,800 bph, it delivers a 69 hours power reserve. [seikata-wm-0761c68649b2]

Also known as: Monster, World Timer

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

37mm

Case Thickness

10.5mm

Lug Width

20mm

Crystal

Mineral

Bezel

Bidirectional

Water Resistance

60m

Dial Color

Green

Jewels

29j

Frequency

28,800 bph

Power Reserve

69 hours

Year

1976

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