Seiko Cal. 5660 - 638

The Seiko 5660-638 represents an important milestone in Seiko's 1984 lineup. Powered by the 5660 caliber with 21j jewels beating at 28,800 bph, it delivers a 42 hours power reserve. [seikata-wm-40938f8ddf8b]

Also known as: Turtle, Tuna

Specifications

Movement

Automatic

Case Material

Hardlex-Coated Steel

Case Width

41mm

Case Thickness

8.8mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

120m

Dial Color

Burgundy

Jewels

21j

Frequency

28,800 bph

Power Reserve

42 hours

Year

1984

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