This device works better than expected. I purchase it with a directional yagi antenna and a directional indoor antenna. The cell tower is 23 miles away, so I get five bars on the roof of my two-story home and one bar on the lower floor. My house is 3,000 sqft, with a metal roof, and I live 10 miles from any town. I used the existing RG-6 cable from the roof to my office. Also, I used a handheld GPS device to point the yagi to the tower and mounted the internal antenna in my office, pointing it to the rest of the house. My wife thought I was wasting our money, but when we went from regularly getting dropping every 30 seconds to two hours regularly on the mobile, she thought it was well spent. After the install, I know get four to five bars throughout the house.Make sure you read the manual. Placement along with stereo, cable, satellite, and electrical wiring will effect this unit.BTW, this is my first review, and thought it worthy to write one.