Originally Posted by Jim harms
What is an EMS ?
Electrical Management System. Will detect faults in a campground power source and shut down the power before your valuable electrical components fry. There are several brands and you have already heard one. We use a Progressive Industries 30A unit. You can generally get a sense of "surge protector" vs EMS by the price. Anything less than $300 is likely not going to help much if the campground has an open neutral or voltage gets too high or low. I am not a huge fan of campingworld.com but they seem to have good prices on Progressive Industries EMS units. We have a 30A trailer and use:
Progressive Industries EMS-PT30X 30 Amp EMS with Surge Protection
As has already been noted, a signature will tell folks immediately what year, make and model of camper you own and add the same for your tow vehicle. UserCP at the top/left of each page and make sure you save it. This will allow more context for answers to questions you pose in the future.