The Class 378 Capitalstar is a type of electric multiple unit that has been ordered for the new London Overground network and franchise. The type is derived from the Class 376 trains currently used by Southeastern, and part of the Electrostar family, but featuring significant differences. Primarily, the Class 378 will feature fully longitudinal seating similar to that used on London Underground rolling stock, which is necessary for the high passenger volume services expected to be run on London Overground. The units will be constructed by Bombardier Transportation, and were initially announced as coming in two separate batches.