Small RAR archive, 156 KB, named for the P8B75-V with the suffix 2.04, most likely the ASUS desktop board of that name at PCB revision 2.04. The name does not state the contents; the size suggests a boardview or similar layout data rather than a full BIOS image, but check after unpacking. Several revisions of this board are catalogued (1.00, 2.00, 2.01, 2.04), so read the revision printed near the PCIe slots or board edge and pick the matching file before relying on part positions.
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.