A prosthesic valve for implantation in a body duct that can cover a range of target sizes by a single device. The valve comprises three main elements: 1) a support cylindrical frame structure that can be collapsed to a small diameter for insertion into the body and that can expand to a large diameter when positioned in the target implantation site, the expansion of the frame being limited by the native valve diameter, which the valve is implanted within. In some cases the frame may be self- expandable 2) A frustoconical leaflet support frame that has an inflow side and an outflow side. The inflow side of the leaflet support frame is attached to the cylindrical frame and can be expanded along with the cylindrical frame to a range of diameters up to the diameter of the body duct, while the outflow side is limited in its opening diameter to a smaller constant diameter 3) Flexible leaflets attached to the leaflet support frame to create a valve that allows flow from inflowe to outflow, but prevents flow in the opposite direction. A delivery catheter dilates the valve while the frustoconical leaflet support system enables the valve to function (open and close) during the deployment process. Unlike prior prosthetic valves that only allow valve expansion, the valve of the invention may be collapsed if needed in order to re position or retrieve the valve.Linvention concerne une valvule prothétique qui est destinée à être implantée dans un conduit corporel et qui peut recouvrir une large gamme de tailles cibles par un dispositif unique. La valvule comprend trois éléments principaux : 1) une structure de cadre cylindrique de support pouvant être pliée en un petit diamètre pour linsertion dans le corps, et pouvant se dilater en un grand diamètre lorsquelle est positionnée dans le site dimplantation cible, la dilatation du cadre étant limitée par le diamètre de valvule dorigine, à lintérieur duquel la valvule est implanté, dans certains cas, le cadre pouvant être auto-extensibl
