This is a mount plate for the Mean Well PT-65B power supply. If you are replacing the internals of an Amiga 500 power supply, you will need to dremel down the case screw shafts and a few other bits of plastic in the case to get the PT-65B to fit in. I affixed the mount plate to the interior of the Amiga 500 PSU with some epoxy. Original idea goes to @ToddsNerdCave on twitter. I just created this mount plate to make it a bit easier.