When you're on the road, why settle for tinny tunes from your phone when you could have the full range of sound through your car stereo? The Smart Tune transmitter sends music digitally from your iPhone, iPod, iPad, smartphone, MP3 player—or any other device with a 3.5 mm stereo jack— to your FM radio. A full range of available frequencies help you avoid interference. Features easy-to-use touchkey controls and hands-free talk function for safer operation. Uses a built-in rechargeable lithium battery, or can be played while attached to the car charger (included). Also comes with a USB to micro USB cable. 2 1/4" w x 1 1/2" h x 1/2" d.