Dometic says about the Ascension FTX 601 Mesh Vestibule
Expand your living space in the outdoors with this optional front vestibule. The vestibule simply and neatly zips onto the tent or the optional front canopy. Whether you are looking for additional protection from the elements and insects, extra privacy or a bit of additional space, this front vestibule with its large door will enable you to maximize your camping enjoyment.