RAR archive of 873 KB carrying code 400-1-4-01-RA, a near duplicate of a similarly named file but slightly larger, so the contents may differ. The name gives no brand or device, and RA likely denotes revision A. Inspect both archives before choosing one. Schematics help trace rails and signals, while firmware images must be checked against the flash chip size and written only after backing up the original with a programmer.
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 @cyberlanelectonik. 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)