1pc Audio Amplifier Black 105x50mm Iron Toroid Transformer Cover for Amplifier Color: black Inner Diameter x Height: 104mm x 49mm Bottom Plate dimension: 113mm x 113mm Mounting dimension: 95mm x 95mm Iron thickness: 1mm Mounting screw hole diameter 3.4mm Raw material: Iron Fit for Toroidal transformers protected cover.
eBay