Latex inner tubes are far more supple than normal butyl tubes. They adapt quickly to the tire changing shape while cornering and rolling. The unique Challenge seamless latex inner tube saves more than 3 watts per wheel over a butyl inner tube according to German, Finnish, Belgian, Dutch, UK and Americal testing. Challenge produces the only seamless 'one-piece' latex inner tubes on the market providing a smooth, balanced ride with no pucker or bump like those found on other tubes. Latex tubes are lighter, thinner and more flexible than a butyl tube, increasing your comfort, lowering your rolling resistance, and helping to prevent flats. The tube also includes a removable core Presta valve making them compatible with both inline and external valve extenders.