This is an adapter that converts from a 30-pin Dock connector to Lightning. It's a rare item that is no longer sold on the Apple official website. Using this adapter, you can connect Lightning devices to 30-pin Dock accessories. As it is a genuine Apple adapter, it has a built-in DAC, allowing for charging, data transfer, and analog audio output via USB connection. Although there are third-party products, as far as I know, only the genuine Apple adapter has a built-in DAC and can output audio. I used it in my car audio system. Please understand that this is a used item before purchasing.