Size "56" equates to typical size 58

like sleeping pads

thus guaranteeing extreme reliability even in adverse weather conditions

64 color screen with an ambient light sensor to make it easy to see the metrics that matter most

The graphic pattern on the front

Challenge, Seamless Latex Inner Tube, Tube, Presta, Size:24-32C Size "56" equates to typicalChallenge 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 Includes a removable core Presta valve making them compatible with both inline and external valve extenders