Flow, a charging mast for electric buses of the Hamburger Hochbahn, is equipped with LEDs that give a visual indication of the fast charging process. The mounting of the current transmitter is open to view and results in a slim overall appearance, so that the 5.3 metres tall charging mast requires only a small amount of floor space and unobtrusively blends into the cityscape. The use of glass-fibre reinforced synthetic material as well as the construction with invisible hinges and screws offer good protection against vandalism.