ZIP archive of 4.89 MB with the uninformative name RB2G, giving no brand, model, board number or indication of contents. It could hold firmware, schematics or other service data, so open it and identify the files before use. If a flash image is inside, check its size against the target chip capacity and record the original chip contents before programming. If it is documentation, match the board number on the PCB against the files before tracing rails or replacing components.
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 @gunvantrathore. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip