varaflow what do you guys think?

I was watching spike and saw this varaflow muffler. It has the electronic valve in a glass pack. Guess you can change the tone at will.
i can't find them for sale anywhere, maybe they are not out yet?

http://www.pertronix.com/prod/ex/varaflow/default.aspx

here is a vet with them on

http://www.youtube.com/watch?v=Yb65uT-z3qM&feature=related