Seiko Cal. 5638 - 690

The Seiko 5638-690 represents an important milestone in Seiko's 1965 lineup. The Coin-Edge bezel and 45mm case give it a distinctive presence on the wrist. [seikata-wm-7b636020e3d4]

Also known as: Bullhead, Baby Tuna

Specifications

Movement

Spring Drive

Case Material

Stainless Steel

Case Width

45mm

Case Thickness

15.1mm

Lug Width

21mm

Crystal

Hardlex

Bezel

Coin-Edge

Water Resistance

40m

Dial Color

White

Jewels

32j

Frequency

36,000 bph

Power Reserve

52 hours

Year

1965

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