RAR archive labelled for the SABERTOOTH 990FX motherboard, with no revision, document type or version given in the name. Its 280 KB size suggests a small document or data file rather than a full BIOS image, so extract it and identify the contents first. The 990FX name refers to an AMD AM3+ chipset board. Check the revision printed near the PCI-E slots or board edge, since a separate GEN3 R2.0 variant of this model exists and its files are not interchangeable.
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.
7-ZipWinRARThe Unarchiver (macOS)