A 260 TPI Super Poly casing and ultra light Latex inner tube are contributing factors to Challenge's Grifo 33 Team Edition Tubular Cross Tire being a professional's first choice. But, so is its versatile tread pattern. Dart like arrows are separated with chevron blocks that bite into loose soil, grass, and mud. And transition knobs are spread along the side wall for positive traction when braking late and pushing your bike into high speed corners. For durability, Challenge gives the Grifo extra puncture protection so you can enjoy the benefits of lower tire pressure without the risk. This lets the tire conform the ground, allowing the knobs to operate at their full potential. Challenge's Grifo 33 Team Edition Tubular Cross Tire is available in 700c x 33mm with Black tread and natural sidewall.