Seiko Cal. 5640 - 642

The Seiko 5640-642 represents an important milestone in Seiko's 1973 lineup. With its 20mm lug width and 10.0mm profile, it sits comfortably on most wrists. [seikata-wm-9e86b8d2fa1a]

Also known as: Baby Tuna

Specifications

Movement

Automatic

Case Material

Two-Tone

Case Width

34mm

Case Thickness

10.0mm

Lug Width

20mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

190m

Dial Color

Burgundy

Jewels

23j

Frequency

36,000 bph

Power Reserve

40 hours

Year

1973

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