This kit of Rotax parts, 280-020 tensioner excenter nut, 932-037 Bearing C3, 280-030 Guide pulley, 247-430 Ali spacer, as you will need all these parts when overhauling the tensioner we have made a kit up. will fit MT350, MT500 and other bikes with the 4 cylinder Rotax engine. All these parts can be purchased separately