This adapter is for the Concert III (Symphony II+) radio systems. It allows the use of a portable audio device such as a smart phone, iPod, iPad, or other mp3 player that has a 3.5mm stereo jack (headphone jack). The cable is approximately 4' in length and can be installed using common hand tools. Installation takes about 5 -10 minutes depending on skill level. Please not, this is a custom made item made only when an order for this item is made. Also, the item does not come with the connector plug (as shown in the image) but rather with bare pins so it can be placed right into the existing harness.