I have been using this one for 4 years now. web page

It's a wired one which I think is best. Our's is on the whole time we are in our RV up to 2 weeks straight, I never turn it off. Not just for backing up for us. It helps when changing lanes out on the highway. It also provides security for our cars in tow on a open trailer, even when we are sitting still in a rest area or a campground, always have eye on the car from inside the RV. Been a good one so far.

Camera mounted up top painted red, wired.