"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 Brand MOOSE RACING Vendor Part Number M20062 Duty Standard Inner Tube Valve Stem Type TR-4 (Round Base), Center Metal Valve (Threaded/Nuts) Material Butyl Polymer Mounting Position Front/Rear Product Name Inner Tube Rim Diameter 18" Tube Fits Tire Size 100/100-18, 100/90-18, 3.25-18, 3.50-18, 4.10-18 Type Motorcycle Units Each