The Yaktrax(R) Pro delivers improved traction, confidence and safety on packed ice or snow thanks to its unique steel coil traction system. And, it offers a sturdy forefoot strap for enhanced stability. Move about naturally with the same solid grip that you are accustomed to on dry surfaces in the Yaktrax Pro. SIZE CHART: Small (S): Women's 6.5-10 / Men's 5-8.5 Medium (M): Women's 10.5 - 12.5 / Men's 9 - 11 Large (L): Women's 13 - 15 / Men's 11.5 - 13.5 Extra Large (XL): Women's 15.5+ / Men's 14+ DESIGN: Forefoot adjustable strap ensures a snug, sturdy fit Easy on and off Fits most footwear Allows you to walk naturally on any winter surface with its spike-less, lightweight design Can be worn in temperatures as low as -41degF Made of injection molded thermal plastic elastomer with hand-wound rust-resistant 1.4mm steel coils for maximum strength and durability Provides 360 degrees of traction Reduces the risk of fall and subsequent injury