An endovascular delivery system , comprising: an elongate outer tubular device having an open lumen and opposed proximal and distal ends with a medial portion therein between; a prosthesis holder disposed within said outer tubular device , said prosthesis holder comprising: an axial guidewire extending through said prosthesis holder ; a body surrounding said axial guidewire ; and an outer surface, upon which a prosthesis may be secured prior to delivery; characterized in that said body comprises: at least three generally cylindrical markers aligned in a direction parallel to said axial guidewire and each spaced an equal distance from said axial guidewire with one of the cylindrical markers being a middle cylindrical marker and the other two cylindrical markers being side cylindrical markers ; and at least two perpendicular markers , wherein said perpendicular markers are disposed at a perpendicular angle to the axial guidewire ; wherein each of said generally cylindrical markers are spaced at about 90° intervals as measured around the axis formed by the axial guidewire and separated from the prosthesis guidewire by a suitable known distance; wherein, upon rotation of the proximal portion to a first position, for example an ipsilateral right position or an ipsilateral left position, only the middle cylindrical marker and the two perpendicular markers are visible and, upon rotation of the proximal portion to a second position, for example an anterior-posterior position, only the two side cylindrical markers are visible. an elongate outer tubular device having an open lumen and opposed proximal and distal ends with a medial portion therein between; a prosthesis holder disposed within said outer tubular device , said prosthesis holder comprising: an axial guidewire extending through said prosthesis holder ; a body surrounding said axial guidewire ; and an outer surface, upon which a prosthesis may be secured prior to delivery; an axial guidewire extending through said prosthesis holder ; a body surrounding said axial guidewire ; and an outer surface, upon which a prosthesis may be secured prior to delivery; characterized in that said body comprises: at least three generally cylindrical markers aligned in a direction parallel to said axial guidewire and each spaced an equal distance from said axial guidewire with one of the cylindrical markers being a middle cylindrical marker and the other two cylindrical markers being side cylindrical markers ; and at least two perpendicular markers , wherein said perpendicular markers are disposed at a perpendicular angle to the axial guidewire ; at least three generally cylindrical markers aligned in a direction parallel to said axial guidewire and each spaced an equal distance from said axial guidewire with one of the cylindrical markers being a middle cylindrical marker and the other two cylindrical markers being side cylindrical markers ; and at least two perpendicular markers , wherein said perpendicular markers are disposed at a perpendicular angle to the axial guidewire ; wherein each of said generally cylindrical markers are spaced at about 90° intervals as measured around the axis formed by the axial guidewire and separated from the prosthesis guidewire by a suitable known distance; wherein, upon rotation of the proximal portion to a first position, for example an ipsilateral right position or an ipsilateral left position, only the middle cylindrical marker and the two perpendicular markers are visible and, upon rotation of the proximal portion to a second position, for example an anterior-posterior position, only the two side cylindrical markers are visible. <EOS>