it works well on both my enclosed and 4 place snowmobile trailers, but both of my flatbed trailers that I use for work they are far from being able to stop them. Even if the trailer is empty is won't lock them up. It really suck because I am Afraid of messing up my brakes on the truck. I also have an '02, 04, and 05 all with aftermarket controllers and they will about put you through the windshield.