My 9 year old fantastic fan was starting to die so I ordered a new one. The inside cowling in the Lance was a hair different so I had to dremel the inside panel of the new fan by notching the corners . No biggie. Start to finish the swap took two hours. New fan is Dicored [Self leveling lap sealant inder and around the roof flange to make a waterproof seal} and screwed into place and is purring away. The fan is pre wired. all you need is a + and - set of wires to hook it to. The fan is the same size a a standard camper roof vent so swapped to one of these is fairly straight forward. Another nice feature is that you can set the temperature that you want the fan to come on at. I also have a vent cover that lets me leave it open while driving and in rain or snow