3 GIK Acoustics 242 Art Panels, "brick wall" 3'x3' but one is a misprint (the faded one on the end) so $200 for all While these will obviously work on your wall, they work equally well when placed on reflective items in front of your listening position - especially glass or even wood coffee tables - very easy to hear the difference especially at lower volumes Note: As shown in the 2nd pic, there is a slight smudge on one - this is from the factory, it's not damaged - not sure if it was intentional "antiquing" or not - shows up bold in the picture, but is hardly noticeable in person https://www.gikacoustics.com/product/242-acoustic-art-panels-3-625-inch/