Seals for slide out rooms in recreational vehicles are typically cumbersome in their use and installation.  This is due to several factors.  First, the openings for slide out rooms are not standard in that the wall thickness is not always uniform.  This often forces the use of many seals to cover various wall thicknesses.  It is also possible that the walls are not perfectly even in their thickness.  Shipping seals for slide out rooms can be difficult as well.  Having a C-channel to straddle a recreational vehicle wall near the opening does not usually allow such a seal to be bent so it may be coiled for shipping.  This forces such seals to be shipped in cut lengths.  Thus, many seals for different widths may need to have cut lengths shipped.  As can easily be imagined, this creates an inventory nightmare.