Surge/voltage protectors

I have searched high and low on the internet and the best I could find on under voltage protection was the Progressive Industries which rates their under at 104v and the over at 132. I called Progressive and they advised that that is the best they can do for the lower price, the only other solution would be to get a 6 or 700 dollar power booster. According to the lady at customer service at Dometic USA the main reason for the concern of undervoltage is that at lower voltage the unit draws higher amps which can be damaging to any electronic board in todays world. I plan on going with the Progressive Industries 30 amp portable unit as even though it is 4 volts under the 108 I feel it still may save me in the long run. I wish i knew someone who could calculate the difference in amps at 108 v vs 104 vthat the 13.5 unit uses. Couldn't be too much. Camping World only carries the TRC unit which rates at 102v if you are interested in Progressive Industries unit, Google them and they have a where to buy link on their site.