This Structures modification plate is designed to attach queen bed frames to full size headboards or full bed frames to queen size headboards. * Each Queen modification plate is 5" wide (wider side) x 5-1/4" tall x 3-7/8" wide (shorter side). * This modification plate can also be used to convert king or cal king headboards to king or cal king frames. * Steel construction creates a heavy-duty connection. * Set includes two modification plates, to attach both a headboard and a footboard you"ll need two sets.