Package comprising: - at least one casing of sheet material, particularly of paper sheet material, defining an inner volume, the casing exhibiting a predetermined number of lateral walls defining at least one passage opening delimited by a free edge, said casing comprising at least one engagement portion emerging, starting from at least one lateral wall, inside the inner volume of the casing itself for defining a projection, wherein the engagement portion extends from the free edge of the casing along a direction entering the inner volume, - at least one container of sheet material, particularly of paper sheet material, distinct from the casing and configured for housing at least one product, said container exhibiting a predetermined number of lateral walls defining at least one respective passage opening delimited by a respective free edge, said passage opening of the container being configured for enabling to insert and withdraw the product from the container, said container being at least configurable between: ∘ a first operative position wherein the same container is at least partially housed in the casing, in the first operative position the passage opening of this latter is at least partially defined inside the inner volume of the casing which - in such first operative position - prevents to insert and withdraw the product from the container, ∘ a second operative position wherein the same container is at least partially placed outside the inner volume of the casing, in the second operative position the passage opening of this latter is defined outside the casing and is adapted to enable to insert and withdraw the product from the container, said container comprising - at at least one lateral wall - at least one stop element configured for abutting, in the first operative position, against the engagement portion of the casing for preventing the container to switch from the first to the second operative position, said package comprising at least one slot - defined between at least one lateral wall of the casing and at least one lateral wall of the container - configured for enabling, at least in the first operative position, to insert at least one open device adapted to enable the disengagement of the stop element of the container from the engagement portion of the casing for enabling the container to switch from the first to the second operative position. - at least one casing of sheet material, particularly of paper sheet material, defining an inner volume, the casing exhibiting a predetermined number of lateral walls defining at least one passage opening delimited by a free edge, said casing comprising at least one engagement portion emerging, starting from at least one lateral wall, inside the inner volume of the casing itself for defining a projection, wherein the engagement portion extends from the free edge of the casing along a direction entering the inner volume, - at least one container of sheet material, particularly of paper sheet material, distinct from the casing and configured for housing at least one product, said container exhibiting a predetermined number of lateral walls defining at least one respective passage opening delimited by a respective free edge, said passage opening of the container being configured for enabling to insert and withdraw the product from the container, said container being at least configurable between: ∘ a first operative position wherein the same container is at least partially housed in the casing, in the first operative position the passage opening of this latter is at least partially defined inside the inner volume of the casing which - in such first operative position - prevents to insert and withdraw the product from the container, ∘ a second operative position wherein the same container is at least partially placed outside the inner volume of the casing, in the second operative position the passage opening of this latter is defined outside the casing and is adapted to enable to insert and withdraw the product from the container, ∘ a first operative position wherein the same container is at least partially housed in the casing, in the first operative position the passage opening of this latter is at least partially defined inside the inner volume of the casing which - in such first operative position - prevents to insert and withdraw the product from the container, ∘ a second operative position wherein the same container is at least partially placed outside the inner volume of the casing, in the second operative position the passage opening of this latter is defined outside the casing and is adapted to enable to insert and withdraw the product from the container,