ASUS Rampage III Extreme motherboard archive in RAR format, roughly 399 KB, with a name that states neither the file type inside nor a board revision. Open it with a common archiver to identify the contents, which in repair collections are usually boardview or schematic data. Such files serve for locating parts on a dense layout, following VRM and memory power rails, finding test points and isolating a short. Make sure the PCB revision on the board matches anything noted in the documents before relying on references.
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 @boardview. 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.