Inner Tube 2.75/3.00-18 TR4 Staight Valve Stem - Fits on 80/90-18 | 80/100-18 Motorcycle Inner Tube 2.75/3.00-18 TR4 Valve Stem* TR4 Valve Stem: Straight Stem, Round Shape to fit on rims with a round valve base. Fits on these Tube Type Tires: 2.75/3.00-18, 3.60-18, 80/90-18, 80/100-18, 90/90-18 Heavy duty durable valve stem. Unbeatable performance and value.