Abstract: A closure for a bottle, comprising a cap-shaped closure component; a projection directed inwardly from an edge of the cap-shaped closure component to grip behind an outwardly directed projection at a neck of a bottle; a substantially cylindrical sealing element extending axially from a bottom of the closure component, the sealing element being disposed within the closure component; and a radial projection formed outside of the sealing element and disposed away from the bottom and having a diameter larger than the inside diameter of the neck of the bottle to be sealed by the closure means in such a way that a sealing surface formed by the radial projection tightly rests against an inside surface of the neck in a closed mode. The bottom comprises a cross-sectional slimming disposed radially beyond the cylindrical sealing element, the slimming having a thickness less than the thickness of an adjacent portion of the bottom such that the slimming functions as a hinge.