RAR archive of about 1.92 MB labelled only with the ASUS Z84FM model name; the name does not state whether it holds a schematic, boardview, BIOS or a mix. At this size a schematic PDF or a set of service documents is plausible, but open it to confirm the contents. Material like this is used to trace power rails, identify components around a fault and verify the expected voltages. Before relying on any of it, match the motherboard number and revision printed on the PCB against the documents inside.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @IT_SERVICE_WORLD. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.