RailAir is used as a generic term for these services by the public and airline operators, such as British Airways at Heathrow, and as a specific brand name of some of the services. The Reading to Heathrow RailAir bus allows connection from cities such as Bristol, Exeter, Plymouth and South Wales to Heathrow Airport without having to change at London Paddington. However, it is possible to change trains at Hayes & Harlington and go by train instead, a change at Reading being also required for this service.