The rebooted Saucony Guide ISO offers stability and support for going the distance, but with a new fit thats sure to make your next run, your best. The ISOFIT upper design gives runners a more tailored, adaptive fit for absolute freedom and comfortable movement. Runners who need that extra guidance, will love the continued medial support system. Upper: Dynamic ISOFIT upper for an adaptive, lightweight fit. FlexFilm lightweight yet strong material allows for fewer layers in the upper for a seamless, flexible feel. Padded tongue and heel collar enhance comfort. Flat laces reduce irritation. Midsole: EVERUN Topsole Construction and PWRFOAM midsole provide a lively, resilient ride, continuous cushioning and enhanced energy return properties that deliver an energized running experience. Added midfoot structure for the ideal hold and support for the runner in motion. Outsole: Tri-FLEX provides increased force dispersion over a greater surface area while also delivering optimal flexibility and traction. iBR+ is 33% lighter and provides more cushioning compared to standard blown rubber. XT-900 premium carbon rubber outsole material offers exceptional traction and high-wear properties.