Seiko Cal. 6643 - 531

The Seiko 6643-531 represents an important milestone in Seiko's 1985 lineup. With its 21mm lug width and 10.6mm profile, it sits comfortably on most wrists. [seikata-wm-81c7932cb0d6]

Also known as: Tuna, Emperor

Specifications

Movement

Hand-Winding

Case Material

Stainless Steel

Case Width

39mm

Case Thickness

10.6mm

Lug Width

21mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

170m

Dial Color

Black

Jewels

32j

Frequency

21,600 bph

Power Reserve

62 hours

Year

1985

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