The faceplate detaches and you can carry it with you View larger Switchable US & European Tuner Frequencies The 648UA will not only be able to pick up U.S. frequencies but it will also have the capability to pick up European frequencies. RDS Tuner "RDS" stands for "Radio Data System" and it allows FM broadcasters to send far more than just an analog audio signal out over the air waves. Using a 57 kHz "subcarrier," stations can transmit digital RDS data for reception by RDS-equipped FM tuners. Depending on what the broadcaster transmits and what your tuner can pick up, you can receive information such as the name of the artist/song, name of the station, genre, traffic information, and more. Playback CD±R/RW AudioMP3 View larger Compatible With Audio Output of iPods / iPhones, Smartphones, and MP3 Players You can connect a device that has an Auxiliary output, such as your iPhone/iPod, smartphone, or MP3 player, straight into the Auxiliary input of your head unit. So basically a cable that has (2) 3.5mm audio (male) plugs. Important: Please beware that this feature is not the same as the “Full iPod Control." This feature will only allow you to control your music by clicking on the designated buttons via the face or front side of your unit. View larger USB Memory Port The USB memory port is located on the front of the unit for easy and quick access. View larger RCA Outputs and Wire Harness View larger Front AUX (Auxiliary) In This input in the front of the 648UA that says “AUX” is an interface that allows the input of audio signals for MP3 players, headphones, and portable music players. It is for AUDIO ONLY and not video. View larger SD Memory Card Port The SD memory card port is located directly behind the face plate once it is opened. Output Power: 60 Watts x 4 Channels The 648UA offers 4 channels that can be used to hook up 4 speakers. Typically though, it is a much better practice to have an amplifier running your system.