An archive of repair files (board LA-3961P). Shared as “INTELBRAS_I30_-_COMPAL_LA-3961P_-_REV_0.3.rar” — a .rar file, 940 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 @generalschematics. 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)