Each set comes with a louvre panel, a useful, wide plate which attaches to the wall with screws and can fit several containers of different sizes. Mounting of the boxes is based on an overlap system. It enables firm and stable fastening to the louvre panel, and quick removal when needed. 10 Piece Set Contains 1 louvre panel, 3 black bins (small), 3 blue bins (medium) and 3 red bins (large). 20 Piece Set Contains 2 louvre panels, 6 black bins (small), 6 blue bins (medium) and 6 red bins (large). Images are for illustration purposes only