What Our Gearhead(R) Experts Are Saying:"These speed booties are all about reducing drag and maximizing efficiency. The 550CX fabric molds to the foot and ankle for a smooth aerodynamic profile, while the Zero Cuff design ensures a sleek fit without zippers or Velcro. The silicone grip around the cuff keeps them secure at high speeds. If you're looking for a performance advantage in racing or time trials, these are a must."Developed and tested at the highest levels of racing, the ASSOS RSR Speed Booties S11 are designed for riders chasing every aerodynamic gain. The 550CX warp-knit fabric molds perfectly to the foot and ankle, smoothing airflow and reducing drag, while the seamless Zero Cuff construction eliminates excess material for an uncompromising race fit. A silicone grip integrated into the cuff keeps them securely in place without compromising aerodynamics, ensuring UCI-legal height. The highly elastic Eva Kant material wraps the toe and forefoot, maintaining a sleek, second-skin fit. With wind tunnel-tested performance and a design proven in the pro peloton, these booties offer the ultimate edge in road racing and time trials.