RAR archive of 397 KB for the ASUS A88XM-A, a micro-ATX motherboard with the AMD A88X chipset for FM2+ APUs. The contents are not stated in the name, so unpack it to see whether a boardview or schematic is supplied. These are used to trace the APU core and northbridge VRM, find standby rails and locate the SPI BIOS chip for reprogramming. Open board files in a compatible viewer, and check that the revision printed on the PCB matches.
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.
7-ZipWinRARThe Unarchiver (macOS)