RAR archive of about 11.1 MB for the A1700 receiver, labelled only as version V8 with no build date or minor version in the name. Unpack it to see which exact release and files it contains before choosing it for an update. Firmware like this is used to upgrade a set-top box or recover one that fails to boot, via its loader or by programming the flash chip. Confirm the model and board, and back up the current flash so the original can be restored.
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)