Ergodyne's Trex 6304 Ice Traction Device keeps you from slipping in ice or snow. It features one-piece stretchable rubber construction and uses a contoured "step in" 3D design to easily wrap boots and shoes for a secure fit. Its 12 rugged, heat-treated carbon steel studs provide tenacious grip and stability in winter conditions. Trex is flexible in temperatures down to -40 degrees Fahrenheit and comes in sizes that accommodate shoe sizes 5–14.