Seiko Cal. 5631 - 259

The Seiko 5631-259 represents an important milestone in Seiko's 1965 lineup. The Rotating bezel and 39mm case give it a distinctive presence on the wrist. [seikata-wm-22771a0495a2]

Also known as: Baby Tuna

Specifications

Movement

Hand-Winding

Case Material

Hardlex-Coated Steel

Case Width

39mm

Case Thickness

8.4mm

Lug Width

18mm

Crystal

Mineral

Bezel

Rotating

Water Resistance

120m

Dial Color

Navy

Jewels

29j

Frequency

21,600 bph

Power Reserve

50 hours

Year

1965

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