RAR archive of 806 KB for the MSI board MS-171B1 at revision A. The name does not state the document type or the laptop model, but schematics are the usual content of MSI archives of this size. MS-17xx is MSI's own notebook board numbering. A technician can use it to trace the DC input and charger path, check the CPU and GPU regulator rails and locate components behind a short. Verify the PCB number and revision against MS-171B1 rev A before relying on the circuit details.
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 .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.