A Ressence comes without a crown, but has a system that is slightly reminiscent of that of the old Harwood watches. Slightly, because Ressence take on it is far more advanced and compares to the Harwood system like the Wright Flyer to the Enterprise. By turning the back of the watch in different ways, not only can the watch be wound but different functions can be set. By making this gearing system gravitational, they simply disengage when the watch is turned over again, with the dial side up. Pure simplicity and elegance.
source: revo-online.com by MARTIN GREEN