Seiko Cal. 5631 - 277

The Seiko 5631-277 represents an important milestone in Seiko's 1971 lineup. The Bidirectional bezel and 36mm case give it a distinctive presence on the wrist. [seikata-wm-7c285abccf85]

Also known as: Helmet, Bellmatic

Specifications

Movement

Kinetic

Case Material

PVD Black

Case Width

36mm

Case Thickness

14.8mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Bidirectional

Water Resistance

70m

Dial Color

Champagne

Jewels

35j

Frequency

21,600 bph

Power Reserve

40 hours

Year

1971

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