Seiko Cal. 6643 - 927

Released in 1976, the Cal. 6643 with design code 927 was part of Seiko's domestic market collection. With its 20mm lug width and 14.0mm profile, it sits comfortably on most wrists. [seikata-wm-fee70bdf1cd3]

Also known as: Sumo

Specifications

Movement

Hand-Winding

Case Material

Hardlex-Coated Steel

Case Width

34mm

Case Thickness

14.0mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

200m

Dial Color

Silver

Jewels

25j

Frequency

21,600 bph

Power Reserve

44 hours

Year

1976

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