The first multi-sport cycling shoe to earn Shimano s top tier S-PHYRE designation, the TR903 are the ultimate choice for speedy transitions and peak pedaling performance Race-Tuned Closure System: Micro-adjustable BOA Li2 dial paired with fast-drying T1 Quick Strap deliver a truly precise fit with no energy wasting fore/aft or up/down foot movement Cool and Dry: Water-resistant synthetic microfiber upper utilizes variable size perforation holes and a pair of mesh panels over the forefoot to boost ventilation and promote quick drying Power Transfer: Stiff carbon sole and low stack height midsole that places your foot closer to the pedal axle combine to deliver efficient pedaling performance Engineered Support: Supportive heel stabilizer cradles foot in optimal power producing position