The present invention is directed to a sealing means for sealing of a neck of a container, especially a container for carbonated beverages. The sealing means comprises a radially deformable outer sealing means suitable to be engaged with an outer free surface of a neck of the container. The outer sealing means comprises an annular base which blends by a blend into a vertical top surface and at least one annular sealing ring arranged at a free end of the annular base, protruding radially inwardly above the inner surface of the base and forming in engaged position with the neck a first contact area with the outer free surface.