The Yaktrax Pro Traction device gives you instant confidence in snowy or icy conditions. The unique steel wire footbed is friendly to indoor surfaces and offers secure purchase on slippery surfaces while the top strap helps keep the Yaktrax on if you run or are wearing especially bulky footwear. Gives you instant confidence in snowy or icy conditions Designed to be more durable for the active winter recreational athlete. This traction device is also great for postal, construction, safety, and highway workers. Constructed with 1.4mm stainless steel coils that to give you 360 of traction Securely fits over a wide variety of footwear styles and gives traction from toe to heel Removable performance strap keeps Yaktrax Pro in place during heavy use Average weight: 5.7oz Sizes: Small: Mens 5 8.5 Womens 6.5 10 Medium: Mens 9 11 Womens 10.5 12.5 Large: Mens 11.5 13.5 Womens 13 15 Extra Large: Mens 14 Womens 15.5 If you have especially bulky shoes it may be necessary to use the next size up.