RAR archive of about 325 KB for the ASUS P8Z77-I DELUXE mini-ITX motherboard; the name lists no revision or document type. Open it to identify the contents before use, likely a boardview given the size. The dense ITX layout makes a placement map especially helpful when locating small capacitors on rails, VRM parts on the daughter board area, or the BIOS flash chip. Boardview files of this family typically open in OpenBoardView or FlexBV. Match the revision printed on your PCB with anything stated inside.
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.