"Real butyl tubes" made from 100% butyl polymer, unlike other "butyl" tubes, which are blended butyl polymer and natural rubber Each tube is individually boxed with a full range of sizes and valve stem types clearly marked on each box end 100% butyl tubes minimize natural air leakage and maintains air pressure for longer period of time All stems are TR-4 type for valve stem. TUBE 2.75/3.60 90/90-19
