3D printed part to hold a rectangular piece of wood that is 6 1/2 by 9 1/4 by 1/2 inches. The hook is made to fit on a loft bed bar that is 1 inch. I would recommend drilling through the hole again so the edges are more refined. I wouldn't put something ridiculously heavy on it its meant more for the tissues, 1 book, maybe your alarm, ect. Light things that fit.