Boss Audio MGR450B Marine Stereo w/AM/FM/BT [MGR450B]MGR450B Marine Stereo w AM FM BT The Boss MGR450B stereo packs a lot of features into a compact design that fits into a standard gauge opening. Crank up some AM FM radio, or plug a compatible device into the rear USB or AUX inputs. The pre set EQ lets you optimize the sound for your favorite tunes, and the full set of preamp outputs will come in handy if you want to expand your system with marine amps and subs. The backlit LED display lets you see