I have a Trailrunner Scout 14rb and I'm considering adding a fantastic fan and vent. First if all, is the size of the factory vent in these 14"? Not sure how to measure it. And is there any other difference between my little TT and "normal" ones that might complicate installation or make it non-standard? I want to be sure it will fit and that I'll be able to do is because I'll be ordering online and bringing it back to Canada, so returning would be a pain...