Sinn watch 903 st black alligator sinns 903 st watches are well known for the elaborately designed dial nearly 30 steps are needed for the creation of this impeccable display one of the watchs most prominent features is its navigation chronograph that can be used to calculate proportions do conversions multiply and divide a date window is positioned between the 4 and 5 o clock marks additional functionalities include an interior bezel with logarithmic scale uv resistant dial luminous di