RAR archive of about 6.74 MB whose name gives no device, board or file type, only a hint that it may be password-protected. Nothing identifies its contents, so extract and inspect the files before treating them as a schematic, boardview or firmware dump. If it contains a BIOS image, read the board number printed on the PCB and compare it with any label inside, back up the existing flash chip with a programmer before writing, and confirm the image size matches 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 @esquemaseletricos. 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.