They sell water filter system machines. This is an amazing product that removes contaminants from tap water which allows you to wash your vehicles and they dry spot free with no drying. Cars boats RVs whatever is painted and shiny will dry completely spot-free. I like keeping my vehicles clean and used to spend a lot of money at the carwash now I do it myself because drying was most of the work. now I just wash and rinse and walk away. When I return my car is completely dry and spot-free and I drive a black Dodge Challenger. Excellent purchase!