The British Rail Class 165 Networker is a fleet of suburban diesel multiple-unit passenger trains (DMUs), originally specified by and built for the British Rail Thames and Chiltern Division of Network SouthEast. They were built by BREL York Works between 1990 and 1992. An express version was subsequently built in the form of the Class 166 Networker Turbo Express trains. Both classes are now sometimes referred to as "Networker Turbos", a name derived some three years later for the project that resulted in the visually similar Class 365 and Class 465 EMUs.