I bought this for an 81-yr-old friend who has some rather serious heart and breathing problems. We stand a pillow on edge behind the wedge, lay a pillow on top of the wedge to bring it to the top of the upright pillow, then add another (contour) pillow on top of the other two to create a slope with a cradle for his head. It sounds more complicated than it is. It provides enough back support to be slightly upright but not completely so. And the two pillows can be adjusted for more or less height, depending upon his needs. He also has a couple of pillows at the bottom of the wedge, to raise his legs. It is the closest I can get to re-creating the raised head and knees of a hospital bed. The wedge does have a tendency to slide away from the top edge of the mattress, but it is easily shifted back when necessary. I have the deep-pocket fitted sheets, so there is plenty of room to put it under the sheet and make it seem more like part of the mattress than an extra pillow. Personally, I can't sleep on my back, so it would NOT be good for me, but he says it is very comfortable and he sleeps through the night.