We are often told that communication is a key for a successful marriage. This may be true but it is clear that if you want your marriage to work while backing a trailer into a camp site, you need to not just shout instructions you need a plan! We struggled to get this done. I think largely because of my lack of ability to actually back up the trailer let alone back into a rock and tree-lined site designed by M. C. Escher. Enter help via walkie-talkie. This was not our idea but the recommendation of the folks from Long-Long Honeymoon who have an excellent YouTube channel on the joys and travails of RV travel. (Mostly joys) We bought these two made by Arcshell with chargers from Amazon for just a bit under $25 and they work really well. The sound is clear, they announce your channel so you don’t have to guess, they hold a charge for many days and we look very cool using them. We first tried to use our phones but often - and usually with the most challenging site, we would not have cell coverage. We used these several times on our last two trips and they made slotting into a camp site a much easier job. We even followed their suggestion that we drop left and right and use passenger side and driver side, very helpful. Highly recommend. And while we have linked to Long-Long Honeymoon for a long time in our Connections tab here is their web site - http://longlonghoneymoon.com, go and be inspired.
We bought ours at Amazon: https://smile.amazon.com/Arcshell-Rechargeable