This heading covers all motor vehicles designed for the transport of ten persons or more (including the driver). The heading includes motor buses and coaches; trolleybuses (obtaining current from overhead wires); and gyrobuses which operate on the principle that kinetic energy can be stored in a high-speed flywheel and used to drive an electric generator which supplies current to a motor. This heading also includes motor coaches convertible into rail-cars by changing the wheels and locking the steering, the motor remaining unchanged.