Stretch-fit topline binding snugs calf to keep warmth in and cold out. 5mm CR flex-foam bootie with four-way stretch nylon, 100% waterproof, lightweight and flexible. Self-cleaning outsole wraps the entire perimeter to provide maximum protection and stability on steep terrain. Additional achilles reinforcement for added protection. Seamless, quick-clean rubber overlay. Added toe protection with a wrap-up toe bumper. Comfort range of sub-freezing conditions to 85 degree.