Small RAR archive for an H81M-C board with the code BM2AD and the tags DP and MB, about 230 KB. The H81 name points to an Intel H81 chipset desktop board, and the naming matches ASUS microATX models, though no brand is given. The contents are not stated; at this size it is likely a boardview or schematic rather than a BIOS image. Open it with WinRAR or 7-Zip, check the file type, and confirm that the model and revision printed on the PCB match before relying on it for repairs.
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.