Small RAR archive, 115 KB, labelled P5KPL-AM SE, the name of an Asus desktop motherboard model. The archive does not state its contents, but such a small size suits a compressed BIOS file or a short document. Extract it and inspect before use. For firmware, confirm the board is the SE edition, since the SE board may need different firmware from the standard P5KPL-AM, keep a backup of the existing chip and check that the image size matches the flash capacity.
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.
7-ZipWinRARThe Unarchiver (macOS)