Packed file for the ASUS Maximus VI Impact mini-ITX motherboard, 248 KB in RAR format. The name lists neither revision nor content, so extract it to see whether it holds a boardview, schematic or BIOS image. A layout file would usually open in FlexBV or a similar viewer for locating components on this dense board and its riser cards. A firmware image would need a backup of the original SPI chip before reprogramming, and the board revision should be checked against any contents.
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.