Seiko Cal. 5661 - 437

The Seiko 5661-437 represents an important milestone in Seiko's 1979 lineup. It features a Navy dial protected by a Acrylic crystal and offers 60m of water resistance. [seikata-wm-8cf10be615b6]

Also known as: Monster, Sumo

Specifications

Movement

Automatic

Case Material

Two-Tone

Case Width

39mm

Case Thickness

12.7mm

Lug Width

22mm

Crystal

Acrylic

Bezel

Inner Rotating

Water Resistance

60m

Dial Color

Navy

Jewels

35j

Frequency

21,600 bph

Power Reserve

52 hours

Year

1979

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