Abstract: The improvements apply to a textile bag element which is permeable to air but not to dust, with a mouth in which the fixed portion of the vacuum-cleaner can be coupled by means of an adhesive connection, characterized by the arrangement of an element in the form of a flexible and adaptable flat disk fixed permanently in the mouth of the bag and having a hook-and-loop fastening element on its outer face, a second element also being provided in the form of a flat disk which is of similar shape to the first, is provided with a complementary hook-and-loop fastening element on its opposite face, and can be fitted removably on the disk fixed in the bag, the second element having, on its outer face, an adhesive region to which a protective disk is applied.