This presta tube in particular fits tires from 28mm to 32mm. Even though it's pitched as the right tube for the Continental Gran Prix, it's fills the tire completely. This means take care when putting this tube in to avoid pinch flats. All Continental tubes are seamless and mold-cured (vulcanized) to ensure uniform roundness and improved reliability at the valve stem. Each and every tube passes a stringent 100% quality control inspection