Seiko Cal. 6640 - 607

The Seiko 6640-607 represents an important milestone in Seiko's 1983 lineup. With its 20mm lug width and 15.5mm profile, it sits comfortably on most wrists. [seikata-wm-0e1abefc8a94]

Also known as: Sumo, Golden Tuna

Specifications

Movement

Hand-Winding

Case Material

Titanium

Case Width

39mm

Case Thickness

15.5mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Rotating

Water Resistance

190m

Dial Color

Black

Jewels

33j

Frequency

21,600 bph

Power Reserve

40 hours

Year

1983

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