RAR archive of about 360 KB labelled for the ASUS P8Z77-V PRO THUNDERBOLT motherboard; the name gives no detail on its contents or revision. Given its size and the related files in the same series, it most likely holds a boardview, but open it to confirm before relying on it. Boardview files for ASUS boards are usually in FZ format and open with OpenBoardView or FlexBV for locating parts and tracing nets. Make sure the model, including the Thunderbolt variant, and the PCB revision match your board.
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.