SL/R230: Mercedes AMG speed shift option




I needed a 3rd brake light as my one had a crack, (amazingly it was as cheap from stealership as online just £100). While I was there I got talking to the parts guy and he gave me my car's 'Data' card, which shows what options the car had from new and one of these options was AMG Speed shift gearbox.
Can anyone tell me how this autobox differs from normal?
Thanks






