This thing inserts into the cassette player and holds my GPS because i dont want it where it usually goes. My GPS plays MP3s so i want easy access to the screen, right by the stereo. You can place your phone in there as well, just make sure you modify the box to fit your needs. I included 3 different shells for you to work with. One for Droid X both with extended battery and standard will fit., Razr MAXX and my GPS unit. What i did was, i found perfect angle for this thing to face me and glued it so it wont rotate. You can secure the ball by tightening the hose clamp but it will look ugly.