Organize your office, shop, playroom or laundry room with the extra large and sturdy 16 cube storage bookcase. The top and bottom shelves and the outside uprights measure 1.5 inches thick. The interior shelves and uprights are .625 inch thick solid particle board. The item is finished on boths sides allowing you to use it as a room divider. Features Finished on all sides for use as a room divider Easy and sturdy hexhead screw assembly 1.5 inch thick hollow core top and bottom shelves and outside uprights Includes hardware for securely attaching to your wall Interior shelves and uprights are made of .625 thick solid particle board