Stretch-fit top line binding snugs calf to keep warmth in. 5mm CR flex-foam bootie with four-way stretch nylon. 100% waterproof, lightweight and flexible. Additional Achilles reinforcement for added protection. Durable, lightweight rubber outsole. Diamond-textured toe and heel reinforcement. Triple reinforced toe, quadruple reinforced heel. Steel shank for additional arch support. Comfort range of sub-freezing conditions to 85°.