Very small RAR archive, only 37.6 KB, labelled for the Star Track SRT 150 GOLD NEW receiver. At this size it cannot be a full firmware image; it more likely holds a channel list, settings file, loader or notes. Open it to see what it contains before use. For a full reflash, look for a complete image matching the flash chip capacity, and always keep a backup of the receiver's existing data before importing any settings or files.
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 @tvsoftwareworld. 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)