The frame is constructed of 1-inch by 2-inch tubular steel side supports of 16-gauge material. The fabricated bottom cross member is 1-1/2" by 6". Both the keyboard shelf and the optional printer/CPU shelf (not pictured) that mounts to the lower portion of the frame are adjustable in 1 inch increments to 5 inches. They each measure a generous 55" wide and 16" deep. The 55" width will support an 88-note keyboard while the contoured upper shelf can easily accommodate audio and video monitor..