The old inner tube has begun after about 7 years of operation, to produce intolerable whistling in the lower bracket for attachment to the vacuum cleaner. A hole I could not identify, but the whistle was more or less depending on the train and bending. When the new tube is now back knotless. However, I hope that 7 years is not the normal service life for an original Miele product. The price is not cheap, but for an original spare part, in my opinion OK.
