This model has been designed to control the spi-pole car but can also be useful for the genoa or the main car control. Line drivers mount a self tailing sheave which operates in both direction with a textile “gripping” system that is efficient even if the circuit is not under strain and causes no wear in the rope. A clutch pin sets the direction in which the traveler moves, or allows for it to be locked in the required position. The power ratio obtainable with a normal (250 mm) handle is 8 to 1, which is much better than a tackle can offer; moreover, this system has a very limited size and weight.