To strike the balance of protection weight and fit mavic use their tech dry st fabric thats waterproof wind proof breathable and elastic to fit neatly around your shoe for no flapping or extra material it also has fully taped seams and a closed bottom sole made from tough hypalon material the staydown zip is at the rear and around the ankle youve got exo grip mavic39s top spec silicone material for a snug streamlined watertight seal