Seiko Cal. 6647 - 831

The 6647-831 is a sought-after Quartz piece from Seiko's golden era. Powered by the 6647 caliber with 18j jewels beating at 36,000 bph, it delivers a 68 hours power reserve. [seikata-wm-6197c78e2eff]

Also known as: Helmet, Arnie

Specifications

Movement

Quartz

Case Material

Two-Tone

Case Width

44mm

Case Thickness

11.6mm

Lug Width

18mm

Crystal

Acrylic

Bezel

Fixed

Water Resistance

110m

Dial Color

Green

Jewels

18j

Frequency

36,000 bph

Power Reserve

68 hours

Year

1966

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