A car mount that pumps up the volume - twice over! Give your iPhone 4 GPS, podcasts, and phone calls a sound boost. The built-in amplification system in the SoundWave(TM) Sound Amplifying Car Mount doubles the volume coming from your iPhone speaker, making it easier to hear your turn-by-turn directions, calls and more. The cradle mounts in seconds to the windshield or vent and holds your iPhone securely-even when in a case-on the roughest terrain. Cable holder keeps charging cable connected (charging cable not included).