Small archive of 1.24 MB named 3D1-20, with no brand, model or file type in the name. The code may indicate version 2.0 of a 3D1 series, but this cannot be confirmed. Extract it to find out whether it holds firmware, drivers or documentation, and match any identifiers to the hardware. If a chip image is inside, save the original contents with a programmer before flashing. Verify the size matches the chip.
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 @schematicslaptop. 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)