This weather seal is installed around the perimeter of the movable window sash that holds the glass.
It is made of Santoprene rubber and best glued to the window frame using weatherstrip adhesive.
We believe it works on 1956-1961 Avion trailers and other trailers with Woodlin windows. Let us know if you know of other trailers this gasket was used on.
Gasket is approximately .41" along the long side of the L and .30" along the short side of the L.