Pilot's watch with non-detachable rotating bezel, which convinces by the clear appearance and the easy to read dial. It also has some interesting technical features such as magnetic field protection or high water resistance.
Model 657 was a companion model to the existing model 656. The primary difference was a larger case and the addition of the rotating bezel. A “Pilot” model was added in December 2005, though it was not much different from the other models. The model 657 was retired from the catalog in 2012, leaving the larger Sinn 857 to take its place.