Crankcase breather, drive side, with pipe union and nut, all Norton singles. Complete with ball and insert, already adjusted. Original part number: not listed separately until 1950 9531 - crankcase breather complete with pipe A2/707; 17617; 19245 - crankcase breather [A2/708; 17618- crankcase breather pipe ] 3758; A2/10; 16590A; 10995; E3331; A11/298 - pipe with nut (nut only supplied)