Abstract: A device for sealing container openings which uniformly applies a stretch plastic film onto the openings to be sealed. The device comprises a support, preferably flat-shaped, having at least one hole, on which is placed the stretch plastic film, the film is held taut and adherent to the support by means of gluing, magnetic force, pressure, or a counter-pattern. The device can bear a mark or a recognition message, as well as a warning or an advertisement and can also be used for temporary sealing of containers.