Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: Wondering about the working distance. Will this work behind my travel trailer a distance of 22 feet from behind my tow vehicle?
Document: Was fairly easy to install...husband installed so that is on while we are driving (new at pullin travel trailer and paranoid about not being able yo see traffic behind). Works but flickers on and off while driving...maybe intererence in signal. Otherwise works great!
Meets my expectations for the product. It shows back up lines and distance markers. You have to determine the acceptable  marks for your vehicle and use. Depending on your automobile the installation can be rather simple to some what difficult. However, some little time and patience will do wonders for your installation. If I were to do it again I would specify the mirror monitor.
The only thing I am not pleased with is the camera lens. I could be three feet from something and it looks twenty feet away. Bought it so I would not hit things but this is no help at all. Installation, quality, and price is good I need a more realistic view behind me.
This was so easy to install. I had originally bought one that had wiring that needed to be run from the back of the  car to the front. Directions were non existant and it took forever to install. After all the trouble it did not work. We got tired of fooling with it for many hours and removed it and sent it back. We ordered this one and it was installed and working in about 30 minutes. It gives a good picture and has a better mounting option.
Right now, I am trying to make this ugly black camera look a little better on my beige vehicle with gray license plates. A little duct tape helps. I wish I had done better research and bought something that looked nicer, so, buyers regrets. Otherwise, seems to work well, I like the yellow guidelines, although things seem far away.
The unit is working fine now that I've got it all installed. I tried using the supplied red clips to splice the camera wires to the backup light wires, but they didn't complete a solid connection. Not sure if one or both didn't work. Maybe it's just the ham radio operator in me talking, but I say do yourself a favor and do it right the first time -- properly splice/solder/tape the wires and be done with it.
Bliss. But this does require one to run the hot back to the camera. Again, no biggie.I have had no interference problems with the video feed. I attached the camera to the rear bumper with a couple of strong magnets so I can move it if I want. Down low to hook up to the trailer, up higher to see behind me on the road or when parking or to keep on eye on the trailer. The magnets cause no problem.
I can easily make out whatever is behind me while backing up, so it does work as advertised. Good qualities are ease of installation (except for the wire connection issue noted) and value. I do with the picture was more crisp. I did try adjusting the contrast and brightness but that didn't improve it much. Overall a solid product. I'll probably post again once I've had a chance to use it for a few months.
Great piece of equipment for the price. Easy to install works great. Only wish it had distance scale on screen.
The first backup of the day yields a black monitor with the distance graph and no image. At the end of the day with temps up in the 70's and the sun out, the camera system works fine but every morning..same thing, black monitor with distance graph.
Answer: Mine works great behind my 28 foot Terry Trailer.