Universal Polerouter Cal. 138 SS Bumper
Universal changed the movement of the
Polerouter to a micro rotor
after one year of production. You can find great information about Polerouter movements at this link. I am very lucky to have received one of the first generation of Polerouters with a bumper movement. The name bumper was derived from the springs (you can see them at 5 o'clock or below the GENEVE inscription) that limit the rotation of the rotor. Please also note the quite unusual shape of the rotor. It is shaped to align with the gear train bridge. Please note that the left side of the rotor almost touches one of the bumper springs. From the first picture, you can also see that the rotor is actually a lot more massive.
Power reserve miracle!