Design: Pull-tab for convenient on-and-off Height: 12" Calf circumference: 17" Comfort range: -20degF - 50degF In-Shoe Comfort: Lightweight EVA midsole for optimal shock absorption Dual density footbed with memory foam to premium cushioning Antimicrobial bioDEWIX(TM) footbed featuring NZYM(TM) to control odor and moisture 4 mm waterproof CR Flex-Foam neoprene with shock absorption and heat-retention properties Mesh lining for enhanced breathability Durability & Traction: New Vibram(R) Arctic Grip all Terrain outsole combined with XS Trek EVO Traction Lug Technology for maximum grip and strength