 Formerly in service were the single ex-Bremen and the three ex-Munich Type GT6N prototypes, which were withdrawn from service in 2015 after the catenary voltage was raised from 600 to 750 volts.The ex-Bremen tram (the world's first modern low floor tram) was returned to the north-german city for preservation.As a stop gap measure 6 Tatra T6A2D were bought from Berlin's transit agency BVG until the arrival of the Flexity Classic on loan to Stockholm in January and February 2011.