The Class 168 Clubman is a diesel multiple-unit

Diesel multiple unit

A diesel multiple unit or DMU is a multiple unit train consisting of multiple carriages powered by one or more on-board diesel engines. They may also be referred to as a railcar or railmotor, depending on country.-Design:...

 (DMU) train

Train

A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...

 used on services between London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 and the Midlands.
The units were built in several batches from 1997 onwards. The first batch of units was classified 168/0 under TOPS

TOPS

Total Operations Processing System, or TOPS, is a computer system for managing the locomotives and rolling stock owned by a rail system...

 and resembled the Class 165

British Rail Class 165

The British Rail Class 165 Turbo is a fleet of suburban diesel multiple units , originally specified by and built for British Rail, the then United Kingdom state owned railway operator. They were built by BREL at York Works between 1990 and 1992...

 units previously built by BREL at York. The Networker-design cab was an interim solution pending the design of a completely new cab for further Turbostar batches.