Generic Factory Antenna Adapter to Aftermarket Car Dash DVD Head Unit Radio Adapter ISO to Din Antenna Aerial European factory antenna with flat plug to aftermarket radio This adapter is used to install radio in your vehicle. This adapter into the car radio antenna and then install your radio. Fits most types of older DIN car radio aerial socket's. For select 1988-2005 Audi/BMW/Mercedes/VW vehicles, Converts to fit newer type ISO aerial plug.