Under the FAQ section at <a href="http://www.cprusa.com" target="_blank">http://www.cprusa.com</a> they have an answer for a different pump, but say the needed modification is difficult to obtain.
I had a hang on wet/dry with the Rio 600 and it simply quit running for no reason at all time after time. That's when I decided no more Rios and no more equipment that runs Rios.
When I found this site and saw complaint after complaint on them, I wondered why anyone would make equipment that only worked with Rios.