I resisted for years, finally bought a 30 Amp Surge Guard and the first trip out pulled into a site with reverse polarity, open ground and low voltage. No telling how much it saved me. I will never plug in again without it. Incidentally, Camping World right now has an internet special on the Surge Guard brand 30 amp portable for $139.97, Reg $329.99. Don't know how to do a clicky but this is the web site http://www.campingworld.com/shopping/item/Portable-Surge-Guards-With-LCD-Display-30-Amp/58464/&?&affiliateid=5193&gclid=CjwKEAjwr6ipBRCM7oqrj6O30jUSJACff2WHWhaOb8eNLHDfZgvBjmmUIMy1OD2IfAIMMlccwOYQkBoCW8_w_wcB.