Set of 3 Picture Boxes (4 pieces needed per item)A four piece set for wrapping wall art, mirrors, and pictures up to 40" x 60" x 4" depth, with an opening space on the top/bottom. allows you to wrap your mirrors and wall art will fit to size. This 4 piece set extends up to 40" X 60" 4" Depth. When extended in full to 40x60, this does not make a completely closed box. There will be an opening space on top/bottom.