Seiko Cal. 6631 - 963

The Seiko 6631-963 represents an important milestone in Seiko's 1971 lineup. Powered by the 6631 caliber with 18j jewels beating at 28,800 bph, it delivers a 45 hours power reserve. [seikata-wm-db1d03d77a64]

Also known as: UFO, Bellmatic

Specifications

Movement

Kinetic

Case Material

PVD Black

Case Width

44mm

Case Thickness

9.3mm

Lug Width

19mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

80m

Dial Color

Black

Jewels

18j

Frequency

28,800 bph

Power Reserve

45 hours

Year

1971

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