The trainsets of Class VT 11.5 (often simply called TEE) were diesel multiple units built by Deutsche Bundesbahn (DB) in 1957 and used for Trans Europ Express (TEE) services. Perceived as flagships of the DB rolling stock, they carried first-class seating only. When the UIC numbering scheme became effective on 1 January 1968, the power heads of the trainsets were renamed to Class 601 whilst the middle cars became Class 901 according to the DB locomotive classification. They were used for TEE service from 1957 until 1972 and thereafter on German InterCity services.