- Motorcycle Inner Tube 2.75/3.00-21 TR4 Valve Stem* <br> - TR4 Valve Stem: Straight Stem, Round Shape to fit on rims with a round valve base <br> - Fits on these Tube Type Tires: 2.75/3.00-21, 80/90-21, 80/100-21, 90/80-21, 90/90-21, 100/80-21 <br> - Rim diameter: 21" <br> - Valve Type: TR4 (Straight Valve, Round Shape) <br> - Made of Thick Rubber Blend <br> - Heavy duty durable valve stem <br> - Seamless construction <br> - Unbeatable performance and value <br> <p>This item is a universal/custom fit component, and does not have any direct standard/OEM model application <br> Refer to your vehicle's owner's manual for inner tube sizing for your tires <br> Sizing information is provided by the manufacturer and does not guarantee a perfect fit. Please use this chart as a guide only</p> <p></p>