• Material: Tourmaline, Polyester Cotton. • Color: Black, Blue. • Size: 32-34 (the sock measures about 20 centimeters in length) • The package includes: 2 pairs of self-heating socks. • They retain heat quickly when rubbed with the feet. • Promote blood circulation and relieve fatigue. • Suitable for outdoor activities such as climbing, skiing, fishing, jogging, hunting, cycling, and hiking. • The bottom of the socks has a tourmaline design that self-heats.