WarmThe socks have a tourmaline design at the bottom, which heats itself and keeps you warm anytime, anywhere, without the need for electricity, regardless of time or geographical restrictions. Cotton MaterialMade of high strength cotton material, soft, elastic and thickened for comfort. One size fits most men and women Foot MassageUsing high quality natural hotspots to stimulate foot acupuncture points to achieve massage effect, relieve leg fatigue and regulate blood circulation. Using tourmaline socks while walking is a natural and relaxing way to get a foot massage [Ideal for outdoor activities] Keep your feet warm in cold weather. Ideal for hiking, skiing, winter fishing, jogging, winter hunting, cycling, hiking, ice hockey and snow shovelling NoteThe self heating point on the socks should be in contact with the bottom of your feet, not on the bottom of your shoes. 2 pairs of self heating socks are easy for you to change and clean