Shimano S PHYRE Flash Shoe Cover Black Size:XXL The optimised inner and outer CKSP JAAG2 The optimised inner and outer plates of the chain provide a larger contact area with the teeth and ensure better power transfer and better shifting under load from gravel to road PU Coated Stretch Fabric (Made with 48% Recycled Polyester) Ensures Smooth Aerodynamic Surface Across the Foot and from the Toes to the AnkleElastic Aero Fabric from the Ankles Up Features Vertical Grooves That Reduce Aerodynamic DragSeamless Fit Tightly Wraps Around the Cycling Shoe and Over the Ankle Opening while the hook and loop fastener creates a secure fit on the bottom of the shoe and allows for easy removal of the shoe covers when the days speed session has ended