Wobblesticks should be mounted to DN40CF flanges with oversize tubes. A flange as shown in the figure above is ideal. A normal CF40 flange with an inner diameter of 38mm does, depending on it's lenght, eventually reduce the angular range of the wobblestick. "DN35CF" flanges with an inner diameter of 35mm are not suitable for WM40 and WMG40 wobblesticks.