RAR archive of 445 KB for the ASUS B85M-D micro-ATX motherboard, an Intel B85 board for Haswell LGA1150 processors. The name does not say what is inside. At this size it most likely holds a boardview or schematic set rather than a full BIOS image, so check the contents after unpacking. Repair technicians use such material to trace power rails, locate MOSFETs and controllers, and find shorts. Match the revision silkscreened on the PCB to the documents before relying on part locations.
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.