Difference between EMI filter and RFI filter
The RFI filter seems mechanically configured, to fit into a metal bulkhead.
Thus the metal bulkhead serves as excellent shield between input and output wires.
Whereas the EMI filter is intended to be installed on a metal plate (notice that mounting tab on the case), with input wiring and output wiring (in the power lines) able to couple to each other by Electric Fields over the top of the EMI filter.