Seiko Cal. 6637 - 561

Seiko 6637-561

The 6637-561 is a sought-after Automatic piece from Seiko's golden era. Powered by the 6637 caliber with 27j jewels beating at 36,000 bph, it delivers a 46 hours power reserve. [seikata-wm-8817a7c33d19]

Also known as: Helmet

Specifications

Movement
Automatic
Case Material
Hardlex-Coated Steel
Case Width
36mm
Case Thickness
12.6mm
Lug Width
18mm
Crystal
Mineral
Bezel
Inner Rotating
Water Resistance
190m
Dial Color
Green
Jewels
27j
Frequency
36,000 bph
Power Reserve
46 hours
Year
1977

Related Models

seikata-wm-8817a7c33d19