Compressed archive named after the P8H67-I desktop motherboard, an H67 chipset mini-ITX model; the name gives no indication of the document type inside. The 330 KB size points to a boardview or compact diagram set rather than a full firmware dump. Unpack it and identify the file format so it can be opened in the right viewer, such as a boardview tool for component locations and nets. Verify the board revision on the PCB, as the related Deluxe variant uses a different layout and parts placement.
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 @boardview. 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.