RAR archive, 828 KB, identified only by the number 400-1-4-01 and the revision code RA. No brand, device or document type appears in the name, so the material needs to be opened and identified before use. Numbered archives like this usually hold board-level service data, such as a schematic for tracing rails and signals or a firmware image for reflashing. Match the code and revision against markings on the circuit board, and back up any chip before writing data to it.
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 @schematicslaptop. 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.