My new camper has a built-in charging plug. When I hooked up my old solar panel, the charge controller burned out. It turns out that the RV manufacturer reverses the polarity of this plug from every other item to the 12V I have with this type of plug. So I bought this charge controller, cut off the ends of my old controller and soldered/shrunk the wires to it. one (when changing the polarity of the output to the battery). I designed and 3D printed a vented case that allows it to be hung on my RV's battery box and gives it extra protection from the elements. My only complaint is that the description says it's weatherproof and the paperwork that came with it says it needs to be kept. outside of the weather. It appears to be fully sealed and waterproof. My little case I made to assemble it should make it perfect.