Inner Tube 4.00/4.50 - 18 TR4 Straight Valve Stem - Fits on 4.00 - 18, 4.50 - 18, 4.25 - 18, 4.60 - 18, 4.70 - 18, 110/90 - 18 Motorcycle Inner Tube 4.00/4.50-18 TR4 Valve Stem* TR4 Valve Stem: Centered, Straight Stem, Round Shape to fit on rims with a round valve base. Fits on these Tube Type Tires: 4.00 - 18, 4.50 - 18, 4.25 - 18, 4.60 - 18, 4.70 - 18, 110/90 - 18 Heavy duty durable valve stem. Unbeatable performance and value.