I've been using one of these 30A hard-wired Surge Guards in my travel trailer for a couple of years now. I really appreciate the built-in feature where the Surge Guard's flashing LED will alert me to the presence of campground wiring problems, and if this is the case, not pass-through the AC if such a problem exists. Once when staying at a small remote desert campground which produces its own power using a diesel generator, our Surge Guard repeatedly disconnected the campground power when the voltage spiked over 134 volts (a dangerous over voltage condition). While it was annoying loosing power, we were glad the Surge Guard was on duty protecting all of the sensitive electronics in our travel trailer. I can't imagine NOT having something like this in any RV we own... it's CHEAP insurance.