Yaktrax Pro Traction Cleats instantly provide better traction, confidence and safety for walking, jogging, or hiking on packed snow or ice. Pro Traction Cleats fit over shoes and are secured with a durable rubber strap that ensures an excellent fit. Traction is provided by a shaped-edge coil design that provides unequaled stability on ice and snow, letting users move about naturally with the same solid grip as on dry surfaces. Yaktrax Pro Traction Cleats are made of high-strength, abrasion and rust-resistant 1.4 mm steel coils and heavy-duty natural rubber to help the cleats easily conform to the shape of any boot or shoe. Multiple coil angles provide 360 degrees of traction on cold surfaces for stability in all directions. Because Yaktrax Pro Traction cleats have been tested in temperatures as low as -41 degrees Fahrenheit, they can be worn in a variety of environments, from icy Wisconsin streets to packed-snow trails in wintery woods. Yaktrax Pro Traction Cleats are available in small, medium, large, and extra-large sizes to fit most shoes: Small (fits shoe size W6.5-10, M5-8.5); Medium (fits shoe size W10.5-12.5, M9-11); Large (fits shoe size W13-15, M11.5-13.5); X-Larger (fits shoe size W15.5+, M 14+). For oversized shoes or boots, Yaktrax recommends purchasing one size larger than your normal shoe size.