Mitas Heavy Duty Tire Tubes Ultra heavy-duty inner tube for motorcycles, scooters and mopeds. Made from a high quality butyl compound with a 4mm thickness. Features: Made from high quality butyl compound 4mm thickness for heavy duty applications Premium valve construction with galvanized Stem includes two washers, metal + rubber cap Packaged individual pouches with nitrogen-rich atmosphere for extended shelf life Note: Tr-4 and Tr-6 valve stem styles can be used interchangeably.