I bought one of those that sits in the window but it didn't work. My husband said I wasted my money because they only work for about 25 miles from the broadcast signal. I asked why he even opened the pkg. To prove it to you, was his answer. lol I don't think he knew it either before he opened it. hahaha The one on the roof works pretty well but we don't have rotor for it so when the wind blows hard sometimes it moves.