A prosthesis delivery system including a prosthesis mounted on an elongate member. The prosthesis has a locking member positioned on the prosthesis. The locking member includes a reduced diameter portion with two opposing surfaces that are configured to engage opposing proximal and distal sides of a radially extending member on the elongate member to lock or limit the longitudinal position of the prosthesis on the elongate member during delivery of the prosthesis to a treatment site.
