Abstract: A flexible closure is disclosed for resealing opened circular-topped containers of carbonated fluids. The flexible cover has a top portion, and a sealing skirt, the sealing skirt being rigidly attached to the top portion. The top portion has a central relieved portion which is deflectable in response to pressure from carbon dioxide gas escaping from the fluid. The sealing skirt extends from the top portion and is adapted to receive the circular top of the container in sealing relationship. The sealing skirt may be rotated either radially towards the container, by deflection of the central relieved portion away from the contrainer, or radially away from the container by deflection of the central relieved portion towards the container. The flexible closure is therefore easily removed or secured to the opened container, and yet maintains a seal as a result of pressure from carbon dioxide gas escaping the fluid.