Archive for the base ASUS F1A55-M motherboard, 213 KB, compressed with RAR. No suffix or content type is given, so treat the file as unverified until you extract it and confirm what it holds. Most often such packages carry a BIOS image used to reprogram the board's SPI flash. Back up the existing chip contents before writing, check that the image size equals the chip capacity, and make sure the board is not an LE, LK or LX variant.
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)