Item is aluminum alloy disk 6.25 in. Dia, 0.09 in. Thick, with 4.0 in. Diameter hole in center with 4.5 in. Od aluminum alloy tube, 1.38 in. Lg, attached at circumference of hole; id of tube 3.875 in.; four evenly spaced holes 0.266 in. Diameter on disk for mounting