Running between West Middlesex University Hospital and Staines-upon-Thames, it is operated by RATP Dev Transit London.

November 1939 the service returned to Hounslow Bus Station & Egham (Eclipse) still operated by ST vehicles.

Turnham Green Garage (V) adds a Monday-Friday allocation to its existing Saturday work from January 1970.

This arrangement lasted until February of the following year when the whole of the Sunday service started from Hounslow Bus Station and journeys (daily) bifurcated during visiting hours to Ashford Hospital.

They did not however retain the contract when next awarded in September 2011 for 5 years, Abellio was the successful operator using a depot at Twickenham (TF).