Full product specifications and details can be found at the Kenwood website;

http://www.kenwood-electronics.co.uk/products/car/vw/DNX520VBT/

This unit is suited best for those who's car did not come with DAB radio as standard. If you have DAB as standard in your Golf, you should consider the DNX521DAB version instead of this unit. Virtually the same but with DAB.

This is a Volkswagen approved stereo, which was available to be fitted by the main dealer after the car was purchased. It cost less (at the time, when new) to buy the car, drive round the block and then come back and have this fitted than to spec the equivalent VW RNS stereo! Still can be done with the mk7 Golf (different model, DNX525DAB).