This kit is designed for RV water heaters with a built-in heat exchanger. It contains everything you need to add a high quality freeze protected solar water heater to your RV. It simply connects to the heat exchanger that is already in your water heater. The antifreeze in the solar loop is heated by the Heliatos SW-38 solar water heating panels. This panel is robust enough to be mounted on a vehicle at highway speeds, has unbreakable twinwall polycarbonate glazing, and a strong aluminum frame, yet only weighs 12 lbs.