Radio case and amplifier bought in China for a few dollars. Ventilation holes on the sides.
https://www.aliexpress.com/item/1005005547198982.html?spm=a2g0o.order_list.order_list_main.15.50501802f5YCNx
https://www.aliexpress.com/item/32985577006.html?spm=a2g0o.order_list.order_list_main.10.50501802f5YCNx