My trucks don't have the radio jacks to plug in our iPhones and this transmitter allows everyone in the family to listen to their own music any time through the car speakers. If your on the phone you can hear the caller through the speakers too. The little cable allows other cell phones to work with it is just as good. There is a side usb slot so another phone can be hooked at the same time and charge. The music comes through really good and the placement allows for hands free driving, especially if your using your phone with gsp. This is our second time buying theses for other family members because everyone wants one and they kept taking mine.