The advantages of the Continental Unitube system. Multi size tubes allow greater compatibility with more tire sizes, and fewer tubes. Unitubes are available in both Schrader and Presta valve tubes. Presta valves are available in a variety of lengths. All 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. This is Continental's product range of tubes for smaller tires, i.e. in diameter equal to or smaller than 24 inch.