Compressed archive for the ASUS-style SABERTOOTH 990FX GEN3 desktop board, revision R2.0 as stated in the name. The name does not say what the archive holds, so at 342 KB it could be a schematic, boardview or partial firmware; open it and inspect the contents before relying on it. The 990FX chipset belongs to AMD socket AM3+ platforms. Always compare the revision silkscreened on the PCB with R2.0, because component placement and rails can differ between board revisions.
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.