1pc Black Iron 120x57mm Toroid Transformer Protector Cover for HIFI Amplifier Color: black Inner Diameter x Height: 120mm x 56mm Bottom Plate dimension: 130mm x 130mm Mounting dimension: 105mm x 105mm Iron thickness: 1mm Mounting screw hole diameter 3.4mm Raw material: Iron Fit for Toroidal transformers protected cover.
eBay