This is my first service walk-through, for which I've chosen this well know Seiko movement. It has a lot of similarities and common parts with the 7S and 4R families. The most notable differences are a separate bridge for the auto winding, and a better mainspring giving 50 hours power reserve. Also, the tiny anti-shock for the train wheels (of debatable usefulness) are not present. Some version have a cotes de Geneve finishing, the one pictured does not. Just like the others it is quite easy to