Cyclocross World Champion for years. Whether a Pro or just a hard core rider Challenge Grifo Open 700C Clincher Folding Cyclocross Tyre is the tyre you need. Unbelievable grip with no rolling resistance compromise. This tyre has Challenges Open Tubular (Clincher style) design. A special fabric is placed between the tread and casing to increase puncture resistance ”PPS” (Puncture Protection Strip) technology.