Cats simply will not use it.
I bought this over two years ago now. One cat has not touched it and the other has used it half a dozen times. Several months ago, I had a parcel delivered. Both cats LOVE jumping in the cardboard box and sharpening there claws in it! I now always keep an empty box in the living room for them. It is a bit messy with bits of cardboard all over the floor but the cats love it and that is all that matters!! I also have a mat (well actually a free carpet sample!) in the hall and cats use it for scratching too!! So all in all the Scratch Wave was a waste of money!!!