I bought this with the intention of using it in my camper when I am in an area with known bad reception. Being winter and here in Colorado with the snow depths in the mountains camping is not desirable. SO, I wanted to try this thing out so if it was a dud I could return it. Went up to a known spot where I get really bad reception, mounting the outside antenna just outside of my truck and plugging the unit in to a small power inverter in the cab. I was very pleased to see my AT&T phone go from 1 bar and not able to make reliable calls to FULL bars and very clear calls. So here is the downside (or upside) to the unit.