SkiTrax have a unique patent Roll Sole design that promotes natural walking motion. SkiTrax will ski boot soles from excessive wear ensuring a proper fit in ski bindings. SkiTrax will also enhance traction when walking on snow and ice. You will be able to walk naturally with confidence in your ski boots. SkiTrax are made with resislant and easy-to-use polyelastomer material which easily adapts to the shape of ski boots. SkiTrax can be worn in temperatures less than 41 degrees Fahrenheit. Size Medium fits Men's Shoe Size 9-11.5 and Women's Shoe Size 10.5-12.5.