FM transmitter allows you to output audio from this navigator to your car stereo speakers. Built-in Hi-Fi speaker, volume adjustable. Button and touch-screen operation. Built-in radar warning system to early remind you of the radar speed measurement test. Intuitive and easy-to-use interface. The navigating software could run the Micro SD card directly. Built-in rechargeable Li-battery which can be powered by travel and car charger. Easily data transmitting, communicate with computer through USB cable. So buy this GPS and you can Save 50% OFF, Now Only $31.99 for Car GPS Navigator with W-488A 4.3 inch TFT Touch Screen, 4GB ROM, Multimedia Function, etc.