Firmware archive for the ASUS U31SD, 1.51 MB as RAR, marked as fixed in the name. That label usually means the image was corrected, for example with a repaired or cleaned region, but the exact change is not stated, so inspect it before use. Such dumps are flashed onto the SPI BIOS chip with an external programmer to bring back a laptop that will not start. Back up the original chip before writing, check that the board revision matches, and make sure the image size equals the chip capacity.
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 @biosarchive. 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.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →