An archive of repair files for Apple hardware (board 820-03348). Shared as “A3186 (820-03348-05 M4 MAX).7z” — a .7z file, 20.1 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 @boardsscanrepo. Enginerys does not host this file.
How to open a .7z file
High-ratio compressed archive, often used for large BIOS collections.
7-ZipWinRARKeka (macOS)