Seiko Cal. 3865 - 631

The Seiko 3865-631 represents an important milestone in Seiko's 1965 lineup. With its 20mm lug width and 15.1mm profile, it sits comfortably on most wrists. [seikata-wm-fd373c2b319c]

Also known as: Tuna, Crown

Specifications

Movement

Automatic

Case Material

Stainless Steel

Case Width

44mm

Case Thickness

15.1mm

Lug Width

20mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

160m

Dial Color

Burgundy

Jewels

26j

Frequency

36,000 bph

Power Reserve

40 hours

Year

1965

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