MSI MS-6501 revision 0B, provided as a ZIP archive of 819 KB. The name says nothing about the contents, so the archive should be checked after extraction; a schematic is the most probable document. The MS-65xx prefix follows MSI's own numbering for desktop motherboards. Such drawings are used to map power rails, find test points for CPU and memory voltages, and isolate shorted parts. Revisions 0A, 0C and 1.0 of this board also exist, so verify the revision on the PCB before relying on the pages.
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 @IT_SERVICE_WORLD. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.