Seiko Cal. 5661 - 678

The Seiko 5661-678 represents an important milestone in Seiko's 1978 lineup. Powered by the 5661 caliber with 20j jewels beating at 36,000 bph, it delivers a 36 hours power reserve. [seikata-wm-433abf9c8065]

Also known as: Helmet, Crown

Specifications

Movement

Quartz

Case Material

Hardlex-Coated Steel

Case Width

34mm

Case Thickness

9.6mm

Lug Width

19mm

Crystal

Hardlex

Bezel

Bidirectional

Water Resistance

140m

Dial Color

Navy

Jewels

20j

Frequency

36,000 bph

Power Reserve

36 hours

Year

1978

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