Seiko Cal. 0731 - 645

The Seiko 0731-645 represents an important milestone in Seiko's 1966 lineup. With its 22mm lug width and 9.1mm profile, it sits comfortably on most wrists. [seikata-wm-7e6efa872120]

Also known as: Tuna, Arnie

Specifications

Movement

Quartz

Case Material

Gold-Plated

Case Width

36mm

Case Thickness

9.1mm

Lug Width

22mm

Crystal

Sapphire

Bezel

Inner Rotating

Water Resistance

90m

Dial Color

Black

Jewels

30j

Frequency

28,800 bph

Power Reserve

71 hours

Year

1966

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