https://www.amazon.com/KKmoon-Revers...9049359&sr=8-6
The sensors are a kind of singular technology.
Find a display you like and all else is about the same.
My $17 unit works just fine.
It's worthless if you have a camera, but it works just fine.
My camera sees my rear wall. I can put the rv within a half inch of anything.
What about your camera isn't letting you see the rear of your vehicle?