MATERIALS: 93% acrylic, 6% polyester and 1% Spandex. KEEPS FEET WARM: These socks are ideal for cold weather because they??re specifically designed to trap heat. They have a brushed inner lining that insulates feet, keeping them warm and toasty. SOFT & COMFY: Trade in your son??s heavy slippers and itchy wool socks for these unbelievably plush socks by Hot Feet. Their soft brushed liner is super comfortable and helps keep his feet warm. MADE ESPECIALLY FOR BOYS: These fit USA boy??s sock sizes 6 ?C 2, which is for ages 5 ?C 11. They were designed to stay in place without restricting the legs, so your son can wear them all winter long! EASY TO WASH: Many people worry that fuzzy socks are hard to wash, but that isn??t the case with Hot Feet Thermal Socks. Just machine wash cold. Then, tumble dry low. Do not dry clean, iron, or bleach. MAKES A GREAT GIFT: Everyone loves having warm feet on a chilly day. Our unique socks are ideal for lounging around the house, hiking, running, and more. They make a great, versatile gift for anybody.