Seiko Cal. 5646 - 991

Released in 1974, the Cal. 5646 with design code 991 was part of Seiko's domestic market collection. The Coin-Edge bezel and 36mm case give it a distinctive presence on the wrist. [seikata-wm-492a7bd3be4b]

Also known as: Monster, UFO

Specifications

Movement

Spring Drive

Case Material

PVD Black

Case Width

36mm

Case Thickness

11.7mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

170m

Dial Color

Burgundy

Jewels

23j

Frequency

28,800 bph

Power Reserve

63 hours

Year

1974

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