RAR archive of 2.11 MB tied to the ASUS A8J and A8F notebook series as indicated by the A8J.F naming; the name does not specify the contents or a board revision, though archives of this size usually hold a schematic. Such documents are used for tracing power rails, checking charger and regulator circuits and reading connector pinouts. Unpack it and inspect the files with a PDF or boardview viewer as appropriate. Confirm the mainboard revision on the PCB matches the document before relying on it.
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 @cyberlanelectonik. 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.