Archive tied to the X450LD mainboard at revision 1.1, the earliest of the X450LD revisions listed here. The RAR is 151 KB and its contents are not stated in the name. A file this small usually holds boardview data or a firmware image. Extract it and check the file types before use. Boardview files let a technician find parts, trace nets and probe test points when chasing a short or missing rail. Match the board revision on the PCB to 1.1, since component placement can differ on later revisions.
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.