A boardview (component placement) file (board 18717-1). Shared as “18717-1 Boardview (.CAD) .rar” — a .rar file, 293 KB.
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 @generalbios. 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)