All Metzeler tubes are made from natural rubber blend and feature heavy-duty construction for excellent service and puncture resistanceFor Valve Stem Types, see page ??? FOR RIM SIZE18?INNER TUBE VALVE STEM TYPE EU34G| TR-4| V1-09-1INNER TUBE VALVE STEM TYPE USTR-4 (round base) Center Metal Valve (threaded and nuts)MATERIALRubberPRODUCT NAMEInner TubeTUBE FITS TIRE SIZE120/80-18| 120/90-18| 130/80-18| 130/90-18| 140/70-18| 140/80-18| 150/70-18| 4.00-18| 4.25-18| 4.50-18TYPEMotorcycleUNITSEach