HPE 780968-001-RFB is a renewed 2-slot power supply backplane board for server hardware, corresponding to OEM part 780968-001.
Mounted inside the chassis behind the power supply cages, the board is a backplane component, not a power supply unit. It is for systems configured with two power supply slots.
HPE lists the OEM part for ProLiant ML350 Gen9 configurations, where it can be used to service or restore the server’s power supply cage assembly.