Seiko Cal. 6638 - 678

The 6638-678 is a sought-after Spring Drive piece from Seiko's golden era. Powered by the 6638 caliber with 17j jewels beating at 21,600 bph, it delivers a 64 hours power reserve. [seikata-wm-837b4545d374]

Also known as: Turtle

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

42mm

Case Thickness

10.5mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

200m

Dial Color

White

Jewels

17j

Frequency

21,600 bph

Power Reserve

64 hours

Year

1978

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