Very low cost backup-camera using WiFi cameras?

I actually put together a system that transmits through wifi to my iPad and it did not cost much. I put together the following two components:

Camera

Transmitter

These are not the sellers I purchased from since they are no longer available but products like what I purchased. The range is not going to work on a 30 foot trailer unless like me you get an extension between the camera and the transmitter to get it closer to your vehicle. It is not 4K video but sufficient for what you need.


note: not sure what is happening to the "Transmitter" link. I cannot clean up the extra text.