Continental Compact Tube Hermetic Plus - Schrader 40mm ValveContinental: High quality butyl tube with removeable valve core ideal for regular use. 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. Hermetic Plus options contain a higher butyl amount and wall thickness which retains air longer and improves puncture resistance.