RAR archive of 1.02 MB for the ECS G31T-M7 motherboard. No revision number appears in the name, which is an important gap, because ECS boards often exist in several revisions that need different files. The contents are not described, so open the package with 7-Zip or WinRAR to see whether it holds a schematic or a firmware image. Before using it, compare the revision printed on the PCB with any inside the archive. When flashing, back up the original SPI chip and confirm the image size matches.
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 @cyberlanelectonik. 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.