We purchased one during our first year of fulltiming and are glad we did. It has cut the power when voltage was too low. Accumulative damage can be done with low voltage also, not just surges. Another time a state park pedestal wasn't wired correctly and our surge protector "refused" power to our coach. We were only staying the night, so just unplugged and used no power. We did report the problem, don't know if they fixed it or not. It has also cut power 3 or 4 times with little power spikes. We wouldn't be without one.