The system is essentially two separate main sheets each anchored on opposite sides of the hardtop. You have to adjust both to try and control and shape the mainsail. It was difficult to have go to settings to get a sail shape for different points of sail like you can with a traveler. There is no installed traveler and it's not even available as a option on owners versions.
The first pic on this link gives a look at the design.
http://www.sunsail.com/fleet/sunsail-444-4-cabin-catamaran-yacht
G