Compatibility: iPhone 4, 3Gs & 3G and all Bluetooth enabled phones for wireless audio streaming and hands-free calling * Live, full duplex communication solution: speak and listen at the same time - DSP to cancel echo and reduce ambient noise. * USB port: Charge USB powered devices, including iPhone 3Gs & 3G, iPod, cell phones, MP3 players, and more. * Line out: Allows for direct connection from the device to the Aux port in your car without the need of Fm Transmission. * Line-in: Auxiliary Line-in jack to connect other audio devices, including MP3 player, CD player, portable DVD player, PC, laptop, etc.