Small 152 KB RAR archive labelled for the X450LD with revision 2.1, apparently an Asus laptop board revision, though the name does not say what the archive holds. Its size fits an EC firmware, a boardview or a small BIOS fragment rather than a full flash image. Open it and identify the contents before use. Revision numbers matter on these boards, so check that the revision printed on the PCB is 2.1. If the archive holds a flash image, back up the original chip with a programmer first.
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.