The daily transport of the president of Ireland is a black 2006 Mercedes-Benz S-Class (3.5 petrol). The president receives the highest protection in the land by law. The president's car is driven by a specially trained and armed member of the Garda Special Branch. The motorcade is led by Garda motorbikes to fend off traffic for the oncoming motorcade. A marked patrol car follows and then the president's car proceeds. Two unmarked cars from the Special Detective Unit follow, they are usually BMW 5 Series, Volvo S60 and/or Audi A6, containing armed bodyguards and the president's staff. The president's "aide-de-camp" always travels with him in the cavalcade. The convoy occasionally contains a vehicle from the Garda Emergency Response Unit (ERU) for increased security.