Seiko Cal. 5631 - 661

Seiko 5631-661

This Solar model from 1966 features a 38mm Titanium case. Powered by the 5631 caliber with 30j jewels beating at 21,600 bph, it delivers a 51 hours power reserve. [seikata-wm-a243a9e99c17]

Also known as: Tuna

Specifications

Movement
Solar
Case Material
Titanium
Case Width
38mm
Case Thickness
8.5mm
Lug Width
21mm
Crystal
Mineral
Bezel
Bidirectional
Water Resistance
120m
Dial Color
Silver
Jewels
30j
Frequency
21,600 bph
Power Reserve
51 hours
Year
1966

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