A delivery system for delivering a prosthesis includes a housing, a sheath extending from within the housing, a first rotatable knob, a first pulley coupled to the first rotatable knob so as to be rotatable therewith, a second rotatable knob, a second pulley coupled to the second rotatable knob so as to be rotatable therewith, and a cable coupled to the first pulley and to the second pulley. The cable is coupled to a proximal portion of the sheath. Rotation of the first rotatable knob causes the first pulley to rotate while the second pulley remains stationary thereby causing the first pulley to wind up a portion of the cable and retract the sheath at a first speed. Rotation of the second rotatable knob causes both the first and second pulleys to rotate, thereby causing both the first and second pulleys to wind up a portion of the cable and retract the sheath at a second speed being faster than the first speed.
