iDeck Integrated Car Cassette Adapter for iPhone 4, 3GS and 3G with Hands-free Function Check your vehicle cassette orientation as iDeck cassette adapter does not rotate, and will not work with certain cassette orientations Compatible iPhone 4, 3GS and 3G. Connects iPhone and car audio without any cable Supports Handsfree Function - Talk and Hear caller's voice through your car speakers Clear and rich sound quality and no need of scanning for available frequency