Archive of ESET NOD32 antivirus signature databases dated 10 April 2019, about 116 MB in a zip file. It is not a schematic, boardview or firmware dump, but an offline virus definition set for updating NOD32 without internet access. Technicians sometimes use such bases to scan customer machines in isolated environments. The definitions are outdated, so newer threats will not be detected, and compatibility depends on the installed NOD32 version. Extract it and point the antivirus update settings to the folder.
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 @laptopdesktop. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.