The 5960 has a vertical clutch chrono, opposed to the more traditional horizontal clutch. The horizontal clutch has gear teeth going in and out, giving a minor amount of friction that would eventually create extra drag in the system and theoretically should slow down the watch. The Vertical clutch system doesn't have this problem, as once the two pieces are "married" they spin as one unit, no teeth going in and out. Thus, the 5960 can have the chronograph hand continuously operate.