... with different harness and dip-switch setting Features for Car Audio Support USB.SD.Aux: 1. CD sound quality ,NO FM transmiter ... noisy. 2. Support Widely extend source,USB disk, SD card,(UP to 8GB). mp3/wma format supported ... . 3.Control the device or music from your car audio buttons or steering wheel, such as, DISK+/DISK -, TRACK+/TRACK ...