The British Rail Class 387 is a type of electric multiple unit passenger train built by Bombardier Transportation as part of the Electrostar family. A total of 107 units were built, with the first train entering service with Thameslink in December 2014. The trains are currently in service with Great Western Railway, Govia Thameslink Railway, and Heathrow Express. The Class 387 is a variation of the Class 379 Bombardier Electrostar, albeit with dual-voltage capability (which allows units to run on 750 V DC third rail as well as use 25 kV AC OLE). The class were the final rolling stock orders based on the Bombardier Electrostar family with 2,805 vehicles built over 18 years between 1999 and 2017.