Seiko Cal. 6691 - 636

Released in 1972, the Cal. 6691 with design code 636 was part of Seiko's domestic market collection. The Coin-Edge bezel and 44mm case give it a distinctive presence on the wrist. [seikata-wm-6289983ed4eb]

Also known as: Helmet, Golden Tuna

Specifications

Movement

Quartz

Case Material

Two-Tone

Case Width

44mm

Case Thickness

13.1mm

Lug Width

19mm

Crystal

Acrylic

Bezel

Coin-Edge

Water Resistance

170m

Dial Color

Black

Jewels

31j

Frequency

21,600 bph

Power Reserve

51 hours

Year

1972

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