Second 4.00 MB BIOS file for the 4320S model, distinguished from its twin only by a copy suffix in the name. It could be the same image or a different unit's dump; checking hashes or a hex diff will tell. Board number and version are not stated. Use it to reprogram the SPI flash with a hardware programmer when the original firmware is corrupted, but read and save the existing chip first and make sure the image size matches the flash capacity on your board.
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 @biosfilebins. Enginerys does not host this file.
How to open a .bin file
A raw, byte-for-byte image of a flash chip: the main BIOS / UEFI, the embedded-controller (EC) firmware, or both.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →