903 H4 is a navigation chronograph by Sinn.
Unlike the other navigation chronographs of Sinn (Sinn 903 St), which are provided with self-winding movement, this model operates in the classic way with manual winding. Thereby via glass bottom an unobstructed view of the movement opens up, because no rotor prevents the free view.
As manual winding movement the rare 1883 by Lemania is used. The watch offers a hands date and also a moon phase indication.
Movement:
Case:
Functions:
Dial:
Bracelet:
Warranty: