1.Size:300-18 2.Material: butyl rubber 3.Rubber content:30% 4.Various ... -proof and maintenance-free Butyl motorcycle tube 300-18:High Tensile Strength & rubber contentUnique feature of anti-aging, good gas-tightnessMaterial: natural rubber ... -17,250-18,300-17,300-18,225-16,250-16,275-16,300-16,350-16,225-17,275-17,225-18,275-18,350-18,250 ...