High Fidelity. Anti-interference. Good Signal. Stereo Extended. Music Tone Pure and Clean. The 3.5 plug of connect to the AUX interface of the car , the USB interface connect to the U disk. Implement auto plays of USB flash disk. Not all the car with this interface can use this kind of line. Some car AUX without decoding function, so can only use MP3 device, (only car AUX interface have the function of read U disk can use this kind of line) When using, U disk had better not too much specific to the car AUX can support how much capacity.U disk can not have other documents inside and do not establish folder. of MP3 is used. & High Quality Category: D3.5Audio cable Connector: D3.5mm-USB Length: 21cm Color: Black Material: plastic + metal Package Includes: 1 x 3.5mm AUX Audio Plug to USB 2.0 male Converter Cable Cord Note:Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.