Thanks for the great replies. This is an old '79 camper that we are re-doing. It doesn't have any outside receptacles. We did run a line to a receptacle that bypasses the electrical system in the camper to be able to run specific devices straight from the power pole instead of putting the extra load on the old camper electrical box. Someday we will find out more about replacing it. For now though I just wanted to have some way of protecting that bypassing line to electronics. I read about low/high voltage possibility from the power pole and wondered how we could protect from that.