I have one of these and they are really nice. With traditional rv antenna signals one must turn the antenna, scan the tv to determine how many channels are available, turn the antenna again and repeat scan again. Sometimes it can take an hour to fine tune your reception.
With the arrival of the digital age, things get easier. With the new Digital Jack you turn it on and slowly rotate the head and there are 4 blue lights
that signal which direction has the best reception. Once you have the most bars lite, you then program your tv, just once. Programming is done in 5 minutes.
Here is what I'm talking about King Controls JACK Over the Air Digital Antenna White - $119.99
You may find it less expensive elsewhere but again it it a real time saver for those on the road.