butyl bike tube 1.A/V, E/V, F/V, G/V, I/V TR4 valves 2.good quality &after-sales service 3.ISO& ... we take this opportunity to introduce ourselves that we are a professional manufacturer established in 1998 and specialising in produce bicycle ... have natural rubber tubes and butyl tube with A/V, E/V, F/V, I/V, G/V, TR4 valves etc. As follows are the available ...