ZIP archive for the Gigabyte GA-B85M-D3V desktop motherboard, a micro-ATX board based on the Intel B85 chipset as its model name indicates. The 660 KB size points to a schematic or service document rather than a BIOS image, but the name does not say which, so check the contents. Gigabyte prints the board revision near the slots, and it should match the revision on the document. A schematic helps trace CPU VRM phases, standby rails, SIO control and the power-on sequence when a board stays dead or loops at startup.
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 @cidschematicandboardviewofficial. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.