I bought this unit to charge my iPhone 4S while driving. Is on the supply side: Car Charger for iPhone 4 4S 3 3G 3Gs. In practice, nothing has worked. On the device I discover the note in the form of a sticker: For iPhone 3G / 3GS. IPhone 4S no word! What do you call my such behavior? It's my 2nd case Mumbi devices do not deliver what is promised on Amazon.