we are a factory that mainly produce the motorcycle inner tube and ebike inner tube.our rubber tube made of the natural rubber.the natural rubber is about 30%,the quality is good.we wish our motorcycle inner tube can export more and more countries,and wish more partner use our rubber inner tube.the size including the 300-18 300-17 250/275-17 250/275-18 300-10 350-10 225/250-17 400-12 130/90-15 90/90-18 110/90-16 325/350-16 325/350-18 400/450-12 450/500-12 and so on