The \\\"Pro\\\" in the Diluvio Pro name indicates that this product comes from a request from Team Sky riders for an even warmer bootie for training in cold and wet conditions. Castelli have 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. Key Features4mm neoprene fabric will stand up to the wettest and coldest winter riding conditions Seams are glued and stitched for added protection from the rain Water-resistant YKK® zipper at back Pro fit with added height to cover your 20cm socks Reflective heel and side print for safety 0°-14°C / 32°-57°F Weight:202g Castelli Overshoe SizingS/MM/LL/XL EU Shoe Size36-3940-4344-47 Cycling Overshoes Buying Guide