Stretch-fit topline binding snugs calf to keep warmth in and cold out. CR flex-foam 5mm bootie with four-way stretch nylon. Lightweight and flexible, 100% waterproof. Additional achilles reinforcement for added protection. Seamless, quick-clean rubber reinforcement. Self-cleaning outsole wraps the entire perimeter to provide maximum protection and stability on steep terrain. Added toe protection with a wrap-up toe bumper.