RAR archive of about 1.63 MB whose name carries only the code 4MXSP-RH-01, with no brand, device type or document type stated. The code reads like a board identifier with an RH-01 revision suffix, but its maker cannot be confirmed from the name alone. Open the archive first to see whether it holds a BIOS dump, a schematic or a boardview. Before using any content, compare the code and revision with the silkscreen on the PCB, and if it turns out to be a flash image, read and save the original chip before programming.
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.