RAR package labelled X99-A with version 1.01, a desktop motherboard designation; the name does not state a brand. The archive is 273 KB and its contents are not described. It could contain boardview data for revision 1.01 or a related service file. Unpack it and check what it holds before use. Boardview data helps locate VRM components, rails and test points on a large desktop board. Confirm that the PCB revision marking matches 1.01 before relying on part locations.
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.