Compressed RAR package, 1.66 MB, labelled 4MXSP-RH011 and nothing more, so the device, brand and file contents are not identified. The RH011 ending may be a revision marker, and a sibling copy written with a hyphen as RH-011 exists at the same size, which suggests the same material. Extract and inspect it before relying on it. For a firmware image, check that its size matches the flash chip and keep a backup of the original. For drawings, confirm the board marking matches the name.
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.