Heavy-Duty Quality Materials: Heavy-Duty inner tube made from premium, 100% natural rubber with a TR4 valve stem, our 3.00/3.50-8 inner tube is built for durability and reliability. Trust our for high-quality, long-lasting inner tubes that won't let you down.
These inner tube feel heavier then others I have looked at. The fact they have metal valve stems is a plus rather than rubber I think they last munch longer.