SIZING INFORMATION: Measure the bottom of your medical boot from heel to toe. MEDIUM 10" to 11", LARGE 11.25" to 12", X-LARGE 12.25" to 13", XX-LARGE 13.25" to 14.25" Please do not round up or down when selecting your size. Measure the bottom of the medical boot and then use measurements above. MediTread is a heavy-duty boot cover designed to keep your brace and foot dry and clean. The upper portion is a thick, rugged nylon with an interior coating of polyurethane to keep moisture from entering the boot cover. The ASTM safety rated sole material is non-skid and sized to accommodate wide medical boots and various types of medical shoes. Our covers are machine washable and can be used indoor/outdoor with an average lifespan of 3 to 6 months. Cover is very water resistant, but not completely waterproof and should not be submerged in water, such as taking a bath. (medical boot in picture is for demonstration purposes only - listing is for cover only)