A closure system for a container for liquids or bulk material includes a lid having an upper side, a lower side and a drinking orifice, a closure member for closing the drinking orifice that is positioned at a lower side of the lid and configured to cover an entire surface of the drinking orifice in a closed position, an operating member for manually opening the drinking orifice by a user positioned at the upper side of the lid and connected to the operating member, and at least one recess defined in the lid and disposed relative to the closure member such that, when the closure member is moved from the closed position via the operating member, the at least one recess is at least partially overlapped by the closure member such that a gas exchange occurs between an interior of the container and an environment.

A can lid comprises a base having a weakened contour defining a tear portion, wherein the base comprises a flange, with a rivet at the center of the base, and with an opening tab attached to the rivet structure. Rotatable bottom and top lids are secured to the rivet structure. An external curved guide rim in the bottom lid is slidably fitted in a circumferential bottom groove of the flange, and an external curved guide rim of the top lid is fitted slidably in a circumferential top groove of the flange of the base. The lids are adapted to rotate about the rivet structure independent of each other. Both lids comprises a protrusion disposed in a direction opposite the side of each lid that faces the base. The protrusions of the lids fit tightly against each other when the lids are in an identical position.