Not sure what the deal is with Best Converter, they are supposed to know their stuff, but when i asked about replacing a certain WFCO converter in a WFCO panel, they said Progressive didn't make one to directly fit and wanted to steer me to the Boondocker/Powermax. After some research (reading the instructions) I found the PD4600 series DOES replace the WFCO I wanted to replace, you remove the converter from the steel box, use the plastic bar that is provided and slide the converter in place of the WFCO using the plastic bar to lock it in place and THROW AWAY THE STEEL BOX THE PD CAME IN.
Apparently Best Converter has not done a lot of recent research on some of this stuff.
Charles