The GripOns are ideal for all outdoor winter activities, helping prevent the risk of pulled muscles, fractures and back problems caused by slips or falls on ice and snow. The lightweight pull-on traction is perfect for all footwear including work, hiking and hunting boots, as well as sport, casual and dress shoes. It's just the product for walking the dog or strolling across icy parking lots. Its easy on-off design makes it great for the elderly or anyone making frequent back and forth trips between indoors and outdoors. Medium size fits: 5.5-7 US men's, 6-10 US women's, 36-40 EU. Large size fits: 7.5-10 US men's, 10.5-13 US women's, 41-44 EU. X-Large size fits: 10.5-15 US men's, 13.5-16 US women's, 45-47 EU. Material: Steel, Rubber.