Seiko Cal. 6642 - 831

The Seiko 6642-831 represents an important milestone in Seiko's 1977 lineup. It features a Green dial protected by a Hardlex crystal and offers 110m of water resistance. [seikata-wm-6c171a299097]

Also known as: Helmet

Specifications

Movement

Spring Drive

Case Material

Hardlex-Coated Steel

Case Width

43mm

Case Thickness

11.4mm

Lug Width

20mm

Crystal

Hardlex

Bezel

Coin-Edge

Water Resistance

110m

Dial Color

Green

Jewels

32j

Frequency

36,000 bph

Power Reserve

48 hours

Year

1977

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