RAR archive of 246 KB for the ASUS P8P67-M micro-ATX motherboard, built on the Intel P67 chipset. The name states nothing beyond the model, so the exact content, likely a boardview or schematic given the size, is clear only after extraction. Such service data helps locate VRM components, trace standby and main power rails, and find parts on a shorted line. Boardview layouts open in OpenBoardView or similar tools. Check the revision silkscreened on the PCB against the document before relying on it, since ASUS layouts can change between revisions.
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.