The present invention relates to an apparatus, in particular for attaching to the back of a seat. The apparatus comprises a plate with a flat recess and an insert which is removably mountable in the flat recess of the plate and is configured to receive an information medium which is viewable when the insert is mounted in the flat recess of the plate. For releasably fixing of the insert on mounting of the same in the flat recess, the insert has the following: at least one tongue on a first border area of the insert for engagement in at least one correspondingly shaped groove in the plate, and at least one releasable fixing that is present in or on at least one second border area of the insert and that is operable by twisting and/or sliding at least one component.