RAR archive for the Gigabyte GA-P41T-D3P desktop motherboard, revision 1.5, around 686 KB. The name does not describe the contents, though Gigabyte archives like this usually hold the schematic in PDF form. It helps with tracing CPU and DDR3 power rails, checking the VRM and locating components around the chipset. A revision 1.4 version of this board also exists, so read the revision printed on the PCB and confirm it is 1.5 before using the drawings for component values or measurements.
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 @IT_SERVICE_WORLD. 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.