... structure 4.heat-resisting, aging resistance 5.Highly Tear Resistant, high airtightness motorcycle inner tube ModelweightRubber contentPulling strengthTensile strengthAir valve 20 ... and abroad, mainly exported to more than 100countries and regions in Asia, North America,Europ,Middle East, South East Asia, Africa ... ,3.50-4 ,3.00-4 , and so on good quality bicycle inner tubes