Ill start with the bad, if you have had a jailbreak done on your iPhone this cable won't work. It took me a while to figure out but after I eliminated the jailbreak this cable allowed me to watch all movies, photos, and listen to my music stored on my iPhone 4 at the same time as charge my battery. It even displayed all artist/title information on the screen even while streaming music from apps like Pandora. I wish the head unit had an input in the rear of it but that's not the cables fault. In conclusion I love the cable for what it allows me to do with the iPhone/iPod through my head unit.