Abstract: The sealing device disclosed herein is designed for providing an air tight seal between a door casing and the sides of a vehicle positioned adjacent the casing. It comprises an elongated rigid angular profile having flanges which define a channel-shaped space therebetween and a resilient and collapsible pad structure fastened in the channel-shaped space between the flanges of the angular profile. The pad structure includes a collapsible spongy material enclosed in an air tight envelope, and the interior of the pad communicates with a vacuum source. In its distended position, the material inside the pad structure will cause the pad to expand a considerable distance beyond the flanges of the angular profile so as to abut the sides of the vehicle thereby providing an air tight seal. When a vacuum is applied to the collapsible material, the pad structure will collapse and be retracted almost completely into the channel-shaped space between the flanges of the profile.