Boss Marine MGR350B is an in-dash marine stereo gauge with chromed bezel and blue backlighting, gauge design with the same aesthetic lines of the other in-dash instruments. Of course it is also equipped with audio input AUX universal compatible with all smartphones and MP3 player. To preserve at best these inputs, USB and AUX ports are protected with a rubber, while the slot for the SD card is located behind the detachable front panel. With bluetooth connection the stereo will stream your music allowing you to control your favourite tunes from your smartphone or MP3 player. Otherwise you can use the USB output for any player or AUX input for the oldest devices. USB and AUX are located behind the stereo, but they can be used on dash with the optional MUSB35 accessory.