London Transport had 700 RF vehicles built. They were based on the underfloor engined AEC Regal IV and had bodies built by Metro-Cammell. Different versions were completed for different applications, though the basic body was always the same. The first 25 intended for private hire operation were two feet six inches shorter than the standard 30 foot version. Early central area examples were supplied without platform doors, but they were fitted retrospectively. Vehicles did change hands between the central, country, private hire and Green Line fleets. In the late sixties a number were heavily modernised to maintain
Green Line services without the expense of purchasing new vehicles. The last survivors of the breed managed to see National Bus green and white livery with London Country. Many have been preserved.
Additionally London Transport designed and maintained a fleet of 65 mechanically similar buses for BEA's operations between the West London Air Terminal and Heathrow Airport and had a batch of 15 ECW bodied RFW class private hire coaches - these were 6 inches wider than the RF at 8 foot.