.rar is a file format used for data compression, and "H20" could be the name of a specific software crack, a game modification, a movie rip, or a music album.
You might be referring to a game, movie (like Halloween H20 ), or software, and accidentally appended the file extension. H20.rar
Could you please clarify which specific file, software, or media you are referring to so I can provide the review you need? a game modification