This cushion was purchased in order to raise the height of the seat on a chair following hip surgery. Not only is the cushion comfortable, it performs the important role of supporting and maintaining the height that you should be at. It is firm enough and sturdy enough to complete this task well. It retained its shape and supporting ability throughout my recovery without sagging or flattening. I have now passed it on to my partner following knee surgery and it still performs as new. I have recently purchased a second cushion to put on a dining chair.