The faceplate detaches and you can carry it with you.View larger Zero Current Draw Memory A lot of us have had the battery of our cars die at one point or another. Sometimes we might just need to replace it. This can mess with all the systems that depend on being hooked up to a power source in order to be able to maintain some saved data. In this case, the 625UAB. It holds information such as the time/date, presets for your favorite radio stations and such. If you ever happen to be without a battery for a short period of time, you will not lose all of this information and have to save them again. All thanks to this little helper. General features Switchable US & European Tuner Frequencies - The 625UAB will not only be able to pick up U.S. frequencies but it will also have the capability to pick up European frequencies.Output Power: 50 Watts x 4 Channels - The 625UAB 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. Playback MP3 Bluetooth Audio Streaming Bluetooth technology is a short-range radio technology that was developed to provide wireless audio and data transmission. Two Bluetooth-enabled devices (like a mobile phone and a car) can be paired so that they establish a communication link when they come within range of each other. Depending on the device, the range can be anywhere from 3 to 300 feet.The 625UAB supports A2DP (Advanced Audio Distribution Profile). A2DP is a Bluetooth profile that allows for the wireless transmission of stereo audio from an A2DP source (typically a phone or computer) to an A2DP receiver (a set of Bluetooth headphones or stereo system). View larger RCA Outputs View larger Compatible With Audio Output of iPod / iPhone, 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 And SD Card Ports The USB and SD memory ports are located in front of the unit for easy and quick access. Bluetooth Hands-Free With this function you are able to answer you phone with just one press of a button. When the call ends you can either hang up first by pressing just one button again or do nothing at all as long as the person you were talking to hangs up first. Just keep on driving without any distractions. View larger Front AUX (Auxiliary) In This input in the front of the 625UAB 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.