You download a single file, yes, but you have to open it to get the two mod files. The rar contains a package and a ts4script. You have to open it, you can't just put it in your Mods folder.
I'm sorry, I don't know any other way to say it. The download is a rar file. You have to open it with a program like 7zip or WinRAR to get the mod inside.