Small 178 KB RAR archive labelled only with the Z96FM board name, without revision or content details. At that size it most likely holds a compact file such as a firmware image or a single document, but that has to be verified after extraction with an archiver. Before using anything inside, match the board name and revision on the PCB, and if it turns out to be a dump for an EC or BIOS chip, back up the existing chip and compare file size with the chip capacity before programming it.
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 @schematicslaptop. 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.