Seiko Cal. 5631 - 881

The Seiko 5631-881 represents an important milestone in Seiko's 1968 lineup. Powered by the 5631 caliber with 18j jewels beating at 36,000 bph, it delivers a 41 hours power reserve. [seikata-wm-4e479a2e833f]

Also known as: UFO, World Timer

Specifications

Movement

Hand-Winding

Case Material

Two-Tone

Case Width

40mm

Case Thickness

9.3mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Bidirectional

Water Resistance

200m

Dial Color

Cream

Jewels

18j

Frequency

36,000 bph

Power Reserve

41 hours

Year

1968

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