903 St, 903 St Black and 903 St Silver are chronographs by Sinn.
Sinn calls this series "Automatic Navigation Chronographs". The peculiarity of the models with the proven automaticchronograph movement Valjoux 7750 lies in the integrated bezel with logarithmic scale division (slide rule function), as it is also known from the Breitling Navitimer.
In addition, the extremely elaborate preparation of the dials impresses. In pure manufacture working in a first of more than 30 operations the surface is finished with a solar grinding (with the black dial variant), as basis for the satin finish. In order to ensure the desired, extremely durable UV resistance, then each dial is also dyed by hand in silver or black with an electrolytic plating method. The result is not only an extremely high-quality appearance with deep, rich luster, but above all absolute color authenticity is guaranteed for many years - and with it a permanent certainty of best readability.
Optionally available with solid polished gracefully built / satin-finishedstainless steel bracelet with milled butterfly clasp, band members for length variation