Castelli Estremo Shoe Covers - Windproof protection from cold and rain - Eye-catching water- and windproof rubber texture gives extra durability - Waterproof zipper on back to keep water out - Rugged, rubberized sole with openings for cleats This is a product where we deviate from our light-is-good philosophy. Some days you just want extra protection for your feet, and the Estremo provides it. We've used a micro-injection covering on the lower portion of this thermal windproof and water-resistant bootie that gives extra warmth and durability. Then we added a waterproof zipper, 3M reflective piping, and an extra-durable sole. And of course we made it so that you'll be getting compliments throughout the ride.