The "Pro" in the Diluvio Pro name indicates that this product comes from a request from our pro riders for an even warmer bootie for training in cold and wet conditions. We made the neoprene 33% thicker and raised the height to cover the lower leg up to just under the calf muscle. The top edge is raw cut to help seal against the skin to keep water out, the seams are sealed like on a wet suit, and the fabric remains very stretchy for great fit and ease in pulling on. Reflectivity on the heel keeps you visible in low-light conditions.