Hi Homer, you said ask so I will. Might seem obvious to some here in Aus, but I was watching some fotage of a guy that makes adaptors to screw oil filters on and make a silencer. It said in the US the adaptor had to be registered, is it the same here and would be illegal to own or is it the "act" of putting it on that then makes it then an illegal item. Just curious and thought you would be the man to ask