 The express train brake had, in addition, a brake pressure regulator in order to prevent the wheels locking when braking quickly.The Kunze-Knorr brake was developed and manufactured by the firm of Knorr-Bremse AG in Berlin.It was also produced by their subsidiary company Süddeutsche Bremsen-AG at what is nowadays the head office of Knorr-Bremse AG in Munich.