Designed for track racers, speedy sprinters, and pure time trial specialists, the S-PHYRE RC903 PWR cycling shoes deliver superb comfort with optimized foot security for efficient pedaling performance when it matters most. FEATURES + BENEFITS • Shimano’s most efficient cycling shoe utilizes a reinforced surround wrapping upper with tongue to deliver a glove-like fit for enhanced rigidity and stability• Race-Tuned Closure System: BOA Li2 metal dial paired with power boost guide and Velcro toe strap reduces foot movement and enhances power transmission• Lock Down: Heel cup with anti-twist stabilization assures optimally secure foot position during intense accelerations and sustained high-cadence efforts• Breathability: Variable size perforation holes in upper increase ventilation and add elasticity, helping accommodate a wider variety of foot shapes• Eye-Catching: New optical coating surface treatment yields dazzling color-shifting crystal finish on outsole and heel• Optimized Power Transfer: Ultra-stiff carbon sole and low stack height midsole that stabilizes foot results in efficient all-day pedaling performance