Design: Seam-sealed waterproof genuine suede upper to keep water and snow out from all angles Made with sustainable genuine leather and suede Waterproof gusset tongue Padded collar and side zipper closure In-Shoe Comfort: 8 mm Zylex(R) felt footbed for added protection and warmth HEAT-MX(TM) sustainable thermal insulation for extra warmth Durability and Traction: Deeplugs for superior traction on snow are also self-cleaning Waterproof and flexible synthetic rubber shell SNOWTREAD synthetic rubber outsole Additional Details: Circumference (based on size 9): 11.25 inches Height: 7.75 inches Weight: 3.3 lbs per pair -40degF comfort rating