Soon as I hit the signal.. I also have my AT4 with every possible option. The ram and Ford can measure your trailer as well, I think this option is available on the 21s now. I just get the camera focused on my trailer, and I really like it. Haven't had a 8.5 width trailer hooked up yet but it all works beautifully on a 6 wide. Sent from my SM-N975W using Tapatalk