Seiko Cal. 6631 - 840

The 6631-840 is a sought-after Solar piece from Seiko's golden era. Powered by the 6631 caliber with 36j jewels beating at 36,000 bph, it delivers a 51 hours power reserve. [seikata-wm-cd82ad7b9a50]

Also known as: Sumo, Crown

Specifications

Movement

Solar

Case Material

Titanium

Case Width

37mm

Case Thickness

12.4mm

Lug Width

19mm

Crystal

Sapphire

Bezel

Coin-Edge

Water Resistance

120m

Dial Color

Champagne

Jewels

36j

Frequency

36,000 bph

Power Reserve

51 hours

Year

1995

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