• Thermal socks made of high-quality polyester cotton, soft to the touch. • Magnetic interior design, must be flipped when worn to activate self-heating. • The bottom of the socks has a tourmaline design that allows self-heating, keeping warmth in cold weather. • One size fits most men and women, ideal for keeping feet warm. • Perfect for outdoor activities such as climbing, skiing, fishing, jogging, hunting, cycling, and hiking, providing comfort and warmth.