Boardview for the ASRock B85 Anniversary desktop motherboard, revision 1.01, contained in a 500 KB RAR archive. It helps locate components and test points, follow nets across both sides of the board and narrow down shorted rails around the CPU VRM or chipset. After extracting, open it in a boardview program that supports the enclosed format. Check that the revision marked on your PCB is 1.01, because part placement and values may differ on other revisions of this model.
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 @BoardSchematic. 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.