Backup dump archive for an ASUS P8H61-M board, labelled BM6620 and described as an old backup. BM6620 likely refers to the ASUS desktop system that shipped with this motherboard. A dump read from a working board preserves serial, MAC and licence data, making it useful for restoring a corrupted chip. Confirm the board revision and flash chip size before writing, and keep your own current dump in case the old image differs in version.
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 @SCHEMATICWORLD. 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)