Unlike Oyster cards, contactless cards also have a 7-day fare cap though it currently only operates on a Monday-Sunday basis. Under 11s can travel free on London buses and trams at any time unaccompanied by an adult; they do not need an Oyster card or a ticket. Children aged 11 to 15 travel free on buses with an 11–15 Oyster photocard; without an Oyster card or Travelcard, they have to pay the full adult fare. Visitors can have a special discount added to an ordinary Oyster card at TfL's Travel Information Centres. There are also concessions for London residents aged 16 to 18. The Freedom Pass scheme allows Greater London residents over state pension age, and those with a disability, to travel free at any time on buses and TfL's rail services. People who have concessionary bus passes issued by English local authorities travel free on TfL bus services at any time. Operators Current Bus services in London are operated by (in order of fleet size): Go-Ahead London, (Blue Triangle, Docklands Buses, London Central, London General, Metrobus) Arriva London Metroline Stagecoach London (East London, Selkent, Thameside) RATP Dev Transit London (London Sovereign, London Transit, London United) Abellio London Sullivan Buses Uno Historic First London Tower Transit – majoriry of operations acquired by RATP Dev Transit London in 2021 with remaining operations under Lea Interchange acquired by Stagecoach London in 2022 HCT Group Each company has its own operating code, and every bus garage in London has its own garage code. Vehicles , the London Buses fleet total of 8,795 buses includes 3,854 hybrid buses, 785 battery electric buses, and 22 hydrogen fuel cell buses. The zero emission fleet is the second largest in Europe, behind Moscow. All buses have been low-floor and accessible since 2006, one of the first major cities in the world to achieve this. The various bus operators providing services under contract to London Buses operate a wide variety of vehicles, about the only immediately obvious common feature being their use of a largely red livery (mandatory since 1997). For each bus route, London Buses sets a specification for buses to be used, with the choice of particular vehicle that meets the specification left up to the operator. Particular examples of London Buses specification include the use of separate exit doors (increasingly unusual on buses in the United Kingdom outside London) and, on double-deckers, the use of