An archive of repair files for HP hardware (board 6050A2356601). Shared as “HP ProBook 6555B (6050a2356601-mb-a02).rar” — a .rar file, 1.22 MB.
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.
7-ZipWinRARThe Unarchiver (macOS)