Seiko Cal. 6631 - 913

The 6631-913 is a sought-after Hand-Winding piece from Seiko's golden era. It features a Navy dial protected by a Sapphire crystal and offers 70m of water resistance. [seikata-wm-0c30622dea12]

Also known as: Monster, Sea Horse

Specifications

Movement

Hand-Winding

Case Material

PVD Black

Case Width

40mm

Case Thickness

10.2mm

Lug Width

18mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

70m

Dial Color

Navy

Jewels

33j

Frequency

36,000 bph

Power Reserve

39 hours

Year

1974

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