A cover for covering food comprising: a base : and a flexible wall extending upwardly from and surrounding said base to define a chamber with an opening, said flexible wall having an initial state where the opening is a first size and having a final state where the opening is a second size different from said first size; wherein the flexible wall includes a first section that extends upwardly from and surrounds the base , the first section having a bottom portion attached to the base , and a top edge spaced from the bottom portion; characterised in that the flexible wall also comprising a second section that extends radially inwardly from the top edge of the first section ; wherein the cover has a maximum opening state (d max ) that may be greater than the initial opening state (d 0 ) whereby upon inserting food of a certain size ranging from the maximum opening(d max ) to initial opening (d 0 ) within said chamber , said second section of said flexible wall compresses, moves or curls downward creating a seal (So) between the food and the cover ; wherein said base further includes a first section having a first thickness (t 1 ) and a second section having a second thickness (t 2 ) less than said first thickness (t 1 ), said second section being located at approximately a center of said first section ; and wherein said base further includes a third section , between the first and second sections having a third thickness (t 3 ), wherein the third section has a third thickness less than said second thickness (t 2 ) and comprises a hinge portion , and wherein the hinge portion is configured to allow the second section to transition between a convex state and a concave state. a base : and a flexible wall extending upwardly from and surrounding said base to define a chamber with an opening, said flexible wall having an initial state where the opening is a first size and having a final state where the opening is a second size different from said first size; wherein the flexible wall includes a first section that extends upwardly from and surrounds the base , the first section having a bottom portion attached to the base , and a top edge spaced from the bottom portion; characterised in that the flexible wall also comprising a second section that extends radially inwardly from the top edge of the first section ; wherein the cover has a maximum opening state (d max ) that may be greater than the initial opening state (d 0 ) whereby upon inserting food of a certain size ranging from the maximum opening(d max ) to initial opening (d 0 ) within said chamber , said second section of said flexible wall compresses, moves or curls downward creating a seal (So) between the food and the cover ; wherein said base further includes a first section having a first thickness (t 1 ) and a second section having a second thickness (t 2 ) less than said first thickness (t 1 ), said second section being located at approximately a center of said first section ; and wherein said base further includes a third section , between the first and second sections having a third thickness (t 3 ), wherein the third section has a third thickness less than said second thickness (t 2 ) and comprises a hinge portion , and wherein the hinge portion is configured to allow the second section to transition between a convex state and a concave state. <EOS>