Castelli aero nano shoecoverthis aero nano shoecover uses water and windproof fabric with sealed seams to keep the water out it doesnt have any insulation so it wont really cover your cold weather rides but its spot on for everything else the upper portion is very stretchy a silicone bead at the top helps prevent water coming in this shoecover has taped seams and a water resistant zip so its ideal for all wet weather conditions featuresaero fit with silicone coated wind and waterproof