a medical device delivery system comprises an inner tube , a medical device disposed about a portion of the distal region of the inner tube , a medical device sheath disposed about the medical device , a medical device sheath retraction device extending proximally from the medical device sheath and an outer sheath disposed about a portion of the medical device sheath retraction device . the distal end of the outer sheath terminates at least one medical device length proximal of the medical device . the medical device sheath is movable relative to the outer sheath and relative to the inner tube .