A container and closure combination, for the containment of fluids and extraction therefrom by way of an extraction tube. The container comprises a closed volume with an opening configured to close the opening of the container; the closure is provided with an aperture such that the closure, upon fitment to the container opening, cannot be removed therefrom. The aperture of the closure comprises a unitary elastic unidirectional valve member that can operate in a first, closed condition, to prevent a flow of fluid from the container; and a second, operational condition, with an extraction tube sealingly engaged with respect to the valve, to permit an extraction of fluid from the container through the tube.