Seiko Cal. 6636 - 991

The Seiko 6636-991 represents an important milestone in Seiko's 1977 lineup. It features a Green dial protected by a Mineral crystal and offers 140m of water resistance. [seikata-wm-e9fb23035e27]

Also known as: Sumo, Sea Horse

Specifications

Movement

Kinetic

Case Material

Hardlex-Coated Steel

Case Width

34mm

Case Thickness

11.5mm

Lug Width

19mm

Crystal

Mineral

Bezel

Coin-Edge

Water Resistance

140m

Dial Color

Green

Jewels

31j

Frequency

28,800 bph

Power Reserve

42 hours

Year

1977

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