Sony CDX-GT40U Listen to your favorite music from a variety of sources with the CDX-GT40U car stereo receiver. Play back your digital MP3, WMA or ACC files, or connect, charge and control your Walkman or other compatible USB mass storage device via the front USB input. There's also a front auxiliary input that lets you connect almost any other portable audio device. An enhanced listening experience is in store thanks to 52 watts of peak power delivered to all four speakers. And with a supplied wireless remote you can conveniently control your music without taking your eyes off the road.