Material: Silicone. Size: XL Silicone material is lightweight, soft, safe, non-toxic and harmless to your feet. Preventing and repairing cracking or peeling, softening dead skin and improving rough skin for foot. Preventing or curing plantar fasciitis, metatarsalgia, corns, calluses, bunions, blister. Air holes can provide enough air for your feet to breathe and wick moisture. Protecting toes by reducing friction between them. Can be worn under or over socks with bare feet, which is reusable and washable. Type: Foot Treatment Function: Foot Protector