I had a very comfortable sofa in a very sunny room and eventually the material started to fall apart.  I tired one of those throw over quilted covers that did not stay on.  I bought this cover that had one piece to cover the couch and three separate pieces, one for each of the three cousins.  It was very easy to get on to a convertible bed sofa, looks fantastic and has remained in place even with people sleeping on it.  I would buy this again and recommend it very highly.