This odd looking gasket was used on most Airstreams from 1950 to 1952 and a number of other travel trailers of that era. Please let us know if it was used on yours. The L wraps snugly around the fixed frame of the window. The bulb cushions the window sash when it closes. Made of silicone rubber. If you need an adhesive with this product use silicone. Will not shrink. Sold by the foot in continuous lengths.