Seiko Cal. 5631 - 664

Seiko 5631-664

The 5631-664 is a sought-after Hand-Winding piece from Seiko's golden era. Powered by the 5631 caliber with 27j jewels beating at 36,000 bph, it delivers a 71 hours power reserve. [seikata-wm-d443a7f09acc]

Also known as: Bullhead, Silverwave

Specifications

Movement
Hand-Winding
Case Material
PVD Black
Case Width
45mm
Case Thickness
12.3mm
Lug Width
20mm
Crystal
Acrylic
Bezel
Coin-Edge
Water Resistance
170m
Dial Color
Black
Jewels
27j
Frequency
36,000 bph
Power Reserve
71 hours
Year
1980

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seikata-wm-d443a7f09acc