loewen has sells them. Dealers can be found by clicking on 'dealers' at the bottom of the page. Know nothing else about them. If the home page comes up look at 'Innovations".
We put one in our 9650 STS and it worked very well. It prevents the chaffer from getting overloaded. The fixed pre-cleaner is way too far open for small grains -- maybe for corn it would work well. We noticed more of an increase in capacity, although the sample was also improved. I believe we bought ours through loewen also.