ONE New Carbonfiber Gooseneck Tube and ONE Nylon Bushing / Coupler. It is a hard dense machined bushing, not a cheap part. and the Id is very close to the ID of one end of the gooseneck. I believe the 30mm deep notches are for the water line ( 8mm wide at the opening and 5.9 mm at the curved end of the notch) i believe the notched end is the brush end.
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