Features: 1.Strong Compatibility: Our inner tubes with metal valve stem, fit 2.75/3.00?21 (front wheel) as well as 90/80 ? 21, 90/90 ? 21, 100/80 ? 21. 2.Universal Fit: Heavy duty inner tubes are suitable for many motorcycles, such as off road motorcycles, dirt bikes, pit bikes, trail bikes. 3.Shock Absorption: Thick butyl rubber absorbs shock, you won't feel bumps and dents, protecting you from external forces, very comfortable. 4.Explosion Proof: When the inner tube is punctured, it instantly creates an airtight seal to prevent injury to the rider, making it safe in any season or weather condition. 5.Good Replacement: Motorcycle inner tubes are easy to install and heavy duty designed to fit most terrains and are a very durable replacement tube. Specification: Item Type: Inner Tube Set Material: Rubber, metal alloy Tube Stem Type: Right Angle Stem Compatible: 2.75/3.00-21 (front wheel) and 90/80 - 21, 90/90 - 21, 100/80 - 21. Applicable: Suitable for off road dirt bikes, pit bikes, trail bikes