2 JBL JRX125 15" 2 Way Speaker PA Bundle High quality silicon gel on the back & sides protect your device from being damaged. Connect your iPhone and CarKit with 3.5mm audio cable, but please do not connect the dock connector cable with your iPhone Use the FM transmitter capabilities as normal When you receive a call, CarKit will switch to hands-free talking through your car stereo Please take care of the distance between the Cigarette Lighter and the shift,so as not to block the shift .