Seiko Cal. 6638 - 990

The Seiko 6638-990 represents an important milestone in Seiko's 1973 lineup. The Fixed bezel and 36mm case give it a distinctive presence on the wrist. [seikata-wm-9ac68f9f8319]

Also known as: UFO

Specifications

Movement

Spring Drive

Case Material

Titanium

Case Width

36mm

Case Thickness

12.9mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Fixed

Water Resistance

60m

Dial Color

White

Jewels

35j

Frequency

21,600 bph

Power Reserve

36 hours

Year

1973

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