RAR archive of 9.69 MB labelled ASUS A7V8X, with no indication of what it holds. At that size it may contain boardview, schematic or BIOS material for the A7V8X motherboard, but the name does not confirm the contents, so open it and check each file before use. Boardviews open in tools such as OpenBoardView, schematics usually in a PDF reader, and a BIOS image is written with a programmer or flash utility. Match the board revision first, and back up the original BIOS chip before writing any image.
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.